Dear peter
what i need is to make a control (button or another) on the vfp native form titlebar.i dont need to cut this titlebar.
see my answer to Naomi in the link.i make some works on subclassing the titlebar.
this one is more difficult because traversing the windows itself with APIs,bindevent,CallWinsowProc,drawing with gdi32..:
if can do that i can make many controls directly on the titebar firing contextuels menu,navigation,and other stuffs. it can be also any control instead a button
read the link i gave:http://www.catch22.net/tuts/custom-titlebar

this can be any window for ex vfp form,internet explorer, notepad.exe.....

Note: for information,there is a vfpx project to subclass titlebar :
https://vfpx.codeplex.com/wikipage?title=ThemedTitleBar&referringTitle=Home