Convert the string 'ÖÖÖÖÖÖHMMM' from UTF-8 to ISO-8859-1:

Widget iconv-test {
    class 'Text'
    expression iconv('UTF-8', 'ISO-8859-1', 'ÖÖÖÖÖÖHMMM')
    width 20
    align 'P'
    speed scroller
    update tack
}

If you look at the code, then it should be easy to understand:

/* iconv function, convert charsets */
/* valid "to" and "from" charsets can be listed by running "iconv --list" from a shell */
/* utf16 & utf32 encodings won't work, as they contain null bytes, confusing strlen */
static void my_iconv(RESULT * result, RESULT * charset_from, RESULT * charset_to, RESULT * arg)