XProfan

Def CharToOem(2) !"USER32", "CharToOemA"
Def OemToChar(2) !"USER32", "OemToCharA"

Proc Text2Ascii

    Parameters Text$
    CharToOem(Addr(Text$), Addr(Text$))
    Return Text$

EndProc

Proc Text2Ansi

    Parameters Text$
    OemToChar(Addr(Text$), Addr(Text$))
    Return Text$

EndProc

Declare AnsiText$, AsciiText$
AnsiText$ = "äöüß"
Print "ANSI: " + AnsiText$ + " = Ascii: " + Text2Ascii(AnsiText$)
WaitKey