1. Con esta instrucción puedes saber si puede ser convertido:
if strconv(strconv(M.lcFileText,12),10) == M.lcFileText
MessageBox('Sí puede ser convertido')
else
MessageBox('No puede ser convertido')
endif
** So in detail, if lcFileText==STRCONV(STRCONV(lcFiletext,12),10), then lcFiletext can be
** UTF-8; if it's not, you would get back questionmarks at positions not having a UTF-8
** characters, as invalid UTF-8 byte combinations don't convert to Unicode and in that step
** already become Unicode questionmarks.
2. Para convertir a UTF-8, puedes usar la recomendación de Martin Krivka en:
MessageBox ( strconv(filetostr("YOUR_TEXT_FILE"),9) )