pase_to_rpg_string_LDADD = /QOpenSys/QIBM/ProdData/OS400/PASE/lib/libiconv.a
Well, then it turned out, the code page "string" specified for ILE C didn't work out. I found out that the code page string should be as shown here. I'm puzzled as to where that guy found the code page string. Then, I finally found that it was AIX code page specification after all, as this link shows. I reproduce it below, just in case (and hopefully IBM doesn't mind ;).
CICS short code name | CCSID | AIX® and Windows code page | HP–UX code page name | Solaris code page name | Description |
37 | 37 | IBM-037 | american_e | IBM-037 | IBMLatin-1 EBCDIC |
8859-1 | 819 | ISO8859-1 | iso8859_1 | 8859 | Latin-1 ASCII (ISO) |
819 | 819 | ISO8859-1 | iso8859_1 | 8859 | Latin-1 ASCII (IBM/ISO) |
850 | 850 | IBM-850 | roman8 | IBM-850 | Latin-1 ASCII |
437 | 437 | IBM-437 | iso8859_1 | IBM-437 | Latin-1 (PC) ASCII |
930 | 930 | IBM-930 | cp930 | IBM-930 | Japanese EBCDIC |
931 | 931 | IBM-931 | japanese_e | IBM-931 | Japanese EBCDIC |
939 | 939 | IBM-939 | cp939 | IBM-939 | Japanese EBCDIC |
932 | 932 | IBM-932 | sjis | ja_JP.pck | Japanese ASCII |
EUCJP | 954 | IBM-eucJP | eucJP | eucJP | Japanese ASCII (ISO) |
942 | 942 | IBM-942 | IBM-942 | IBM-942 | Japanese ASCII |
943 | 943 | IBM-943 | IBM-943 | IBM-943 | Japanese ASCII |
EUCKR | 970 | IBM-eucKR | eucKR | eucKR | Korean ASCII (ISO) |
934 | 934 | IBM-934 | IMB-934 | IBM-934 | Korean ASCII |
944 | 944 | IBM-944 | IBM-944 | IBM-944 | Korean ASCII |
949 | 949 | IBM-949 | korean15 | IBM-949 | Korean ASCII |
933 | 933 | IBM-933 | korean_e | IBM-933 | Korean EBCDIC |
EUCTW | 964 | IBM-eucTW | IBM-eucTW | eucTW | Traditional Chinese |
938 | 938 | IBM-938 | IBM-938 | IBM-938 | Traditional Chinese ASCII |
948 | 948 | IBM-948 | IBM-948 | IBM-948 | Traditional Chinese ASCII |
937 | 937 | IBM-937 | chinese-t_e | IBM-937 | Traditional Chinese EBCDIC |
BIG5 | 950 | Zh_TW.big5 | big5 | zh_TW.BIG5 | Traditional Chinese BIG5 |
946 | 946 | IBM-946 | IBM-946 | IBM-946 | Simplified Chinese ASCII |
1381 | 1381 | IBM-1381 | hp15CN | IBM-1381 | Simplified Chinese ASCII |
935 | 935 | IBM-935 | chinese-s_e | IBM-935 | Simplified Chinese EBCDIC |
EUCN | 1383 | IBM-eucCN | chinese-s_e | eucCN | Simplified Chinese ASCII (ISO) |
GB18030 | 5488 | GB18030 | gb18030 | GB18030 | Simplified Chinese GB18030 |
864 | 864 | IBM-864 | arabic8 | IBM-864 | Arabic ASCII |
8859-6 | 1089 | ISO8859-6 | iso8859_6 | ISO8859-6 | Arabic ASCII (ISO) |
1089 | 1089 | ISO8859-6 | iso8859_6 | ISO8859-6 | Arabic ASCII (IBM/ISO) |
420 | 420 | IBM-420 | arabic_e | IBM-420 | Arabic EBCDIC |
855 | 855 | IBM-855 | IBM-855 | IBM-855 | Cyrillic ASCII |
866 | 866 | IBM-866 | IBM-866 | IBM-866 | Cyrillic ASCII |
8859-5 | 915 | ISO8859-5 | iso8859_5 | ISO8859-5 | Cyrillic ASCII (ISO) |
915 | 915 | ISO8859-5 | iso8859_5 | ISO8859-5 | Cyrillic ASCII (IBM/ISO) |
1025 | 1025 | IBM-1025 | IBM-1025 | IBM-1025 | Multilingual Cyrillic EBCDIC |
869 | 869 | IBM-869 | greek8 | IBM-869 | Greek ASCII |
8859-7 | 813 | ISO8859-7 | iso8859_7 | ISO8859-7 | Greek ASCII (ISO) |
813 | 813 | ISO8859-7 | iso8859_7 | ISO8859-7 | Greek ASCII (IBM/ISO) |
875 | 875 | IBM-875 | greek_e | IBM-875 | Greek EBCDIC |
856 | 856 | IBM-856 | hebrew8 | IBM-856 | Hebrew ASCII |
8859-8 | 916 | ISO8859-8 | iso8859_8 | ISO8859-8 | Hebrew ASCII (ISO) |
916 | 916 | ISO8859-8 | iso8859_8 | ISO8859-8 | Hebrew ASCII (IBM/ISO) |
424 | 424 | IBM-424 | hebrew_e | IBM-424 | Hebrew EBCDIC |
273 | 273 | IBM-273 | german_e | IBM-273 | Austria, Germany EBCDIC |
277 | 277 | IBM-277 | danish_e | IBM-277 | Denmark, Norway EBCDIC |
278 | 278 | IBM-278 | finnish_e | IBM-278 | Finland, Sweden EBCDIC |
280 | 280 | IBM-280 | italian_e | IBM-280 | Italy EBCDIC |
284 | 284 | IBM-284 | spanish_e | IBM-284 | Spain, Latin Am.(Sp) EBCDIC |
285 | 285 | IBM-285 | english_e | IBM-285 | UK EBCDIC |
297 | 297 | IBM-297 | french_e | IBM-297 | France EBCDIC |
500 | 500 | IBM-500 | IBM-500 | IBM-500 | International latin-1 EBCDIC |
871 | 871 | IBM-871 | icelandic_e | IBM-871 | Iceland EBCDIC |
852 | 852 | IBM-852 | IBM-852 | IBM-852 | Latin-2 ASCII |
8859-2 | 912 | ISO8859-2 | iso8859_2 | ISO8859-2 | Latin-2 ASCII (ISO) |
912 | 912 | ISO8859-2 | iso8859_2 | ISO8859-2 | Latin-2 ASCII (IBM/ISO) |
870 | 870 | IBM-870 | IBM-870 | IBM-870 | Latin-2 EBCDIC |
857 | 857 | IBM-857 | turkish8 | IBM-857 | Turkey ASCII |
8859-9 | 920 | ISO8859-9 | iso8859_9 | ISO8859-9 | Turkey ASCII (ISO) |
920 | 920 | ISO8859-9 | iso8859_9 | ISO8859-9 | Turkey ASCII (IBM/ISO) |
1026 | 1026 | IBM-1026 | turkish_e | IBM-1026 | Turkey EBCDIC |
UTF-8 | 1208 | UTF-8 (only) | UTF-8 | UTF-8 | Unicode file code set |
UCS-2 | 1200 | UCS-2 (only) | UCS-2 | UCS-2 | Unicode processing code set |
So, next time, you code on iSeries PASE, use "IBM-037" (EBCDIC code page) and "ISO8859-1" (ASCII 8-bit) strings to convert back and forth.
I hope this post will somehow save somebody someday.