INT 2F - ZyXEL ZFAX v3+ - CONVERT VOICE FILE                                    
	AX = DB22h
	DS:SI -> source filename, including path (max 128 characters)
	DS:BX -> destination filename, including path (max 80 characters)
	CX = destination format
	    00h two-bit ADPCM, 01h three-bit ADPCM, 02h VOC
Return: AX = status (see #03096)
SeeAlso: AX=DB13h,AX=DB20h,AX=DB21h,AX=DB23h