)
Call the XMS driver "Lock extended memory block" function with:
	AH = 0Ch
	DX = handle of block to lock
Return: AX = status
	    0001h success
		DX:BX = 32-bit physical address of locked block
	    0000h failure
		BL = error code (80h,81h,A2h,ACh,ADh) (see #02775)
Note:	MS Windows 3.x rejects this function for handles allocated after
	  Windows started
SeeAlso: #02759,#02761,#02763,#02777