INT 15 U - DESQview/X - ???                                                     
	AX = DE29h
	BX = 0001h
	DX = segment of window handle
Return: CF clear if successful
	    AX = ???
	    DX = ???
	CF set on error
Note:	DESQview 2.50-2.52 are distributed as part of DESQview/X v1.0x.