Associate a custom file type with a custom exe

Hi,

I have "finally" purchased SetupFactory today :lol

my question is how can I associate a new file type with an exe I have installed ? I want that all files with the extension .sgcpo (files created by me) receive the icon of my installed exe (wcp.exe) and when I clic on it, the exe will be launched.

thanks in advance for your reply,
Domi.