Look at the following MSDN article.

Adding a Full Screen Feature to an MFC Application
ID: Q164162

This relies on AdjustWindowRectEx() to create a F11 type zoom function, which is what I believe you are looking at doing to get rid of the caption and gadgets.

This sample can easily be ported to standard C/C++ and maybee VFP using Christof Langs (sorry if I spelt your name wrong Christof) STRUCT toolkit available on UT.