MReservec2pWindows [(]NumberOfWindows.w[)] ; Reserve structure-memory for c2pWindows

This must be called before any operations are performed that have anything to do
with c2pWindow objects, unless making use of the default reserved c2pWindow
objects. This command simply reserves some structure memory in order to hold
the objects, but does not make space for holding any graphics-data. c2pWindow
objects are numbered from 0 upwards. If used as a function, this command will
return the address of where the c2pWindow objects are being stored, or 0 for
failure.