fetch window property with XGetWindowProperty.
if it's some special struct property, you can cast it or use a convenience function
if the property has an 8 bit format, it gives you a nul-terminated char*
if the property has a 32 bit format, it returns an array of 64-bit elements with random garbage stuffed in the high 4 bytes.

i thought i was having a stroke double checking my types. i wonder if xlib is just retarded and uses unsigned long regardless of architecture or what the protocol itself is sending.