Creating a pixmap for an already existing X display

[Joshua Outwater <Joshua Outwater sun com>]

I haven't done X programming before so this question may be extremely dumb.

I already have a X display open and I want to create a GdkPixmap using 
that display.  Assuming I get a handle to an X window how do I convert a 
X window to a GdkWindow so I may pass it to gdk_create_pixmap?  Also, is 
there a way to initialize the toolkit to use that display in general?

Josh