CaptureBmp() doesn't work because you have an out of date version of the standard PocketC library header file. This file is called default.dat and is always included into your program, you don't need a #include. It is expected to be in the same folder as pceditor.exe.
You may need to update the actual library itself.
You can download default.dat from:
Overwrite your existing default.dat with the new one.
You can get the latest copy of the library from the standard download page.
PocketC CE API interface: http://www.networkdynamics.net/PCForm.html#library
PCForm and CE API forum: http://www.networkdynamics.net/forum