INT 21,42 - Move File Pointer Using Handle

	AH = 42h
	AL = origin of move:
	     00 = beginning of file plus offset  (SEEK_SET)
	     01 = current location plus offset	(SEEK_CUR)
	     02 = end of file plus offset  (SEEK_END)
	BX = file handle
	CX = high order word of number of bytes to move
	DX = low order word of number of bytes to move


	on return:
	AX = error code if CF set  (see DOS ERROR CODES)
	DX:AX = new pointer location if CF not set


	- seeks to specified location in file