In this section:
%uw (Include Window) enables existing Windows code to be interfaced with ClearWin+. Given a registered Windows class (that will have its own Windows procedure), a window can be embedded in a format window by using %uw. %uw is followed by a standard character string giving the name of the class. It also takes the following arguments:
1) the INTEGER width of the child in pixels,
2) the INTEGER height of the child in pixels,
3) the Window style (This will be OR-ed with WS_CHILD. In general, no border or caption will be specified, as these will normally be applied to the main window e.g. using %ca (Caption).)
4) the extended window style (often zero),
5) an INTEGER (kind=7) to receive the handle for the resultant child window.