I may not be answering the exact question -- my apologies if this is so.
In case if an application needs to be notified upon data having been placed in the Clipboard, there is a way of doing that without detecting CTRL+C.
The form's window has to be placed in the Clipboard chain (SetClipboardViewer, ChangeClipboardChain API calls). Once done, the form starts receiving WM_DRAWCLIPBOARD notification each time the content of the Clipboard changes.
VFP sample code: How to disable the Windows Clipboard (requires VFP9)
http://www.news2news.com/vfp/?example=488