Opening an Application by double clicking on a file?

Question

I'd like to open one of my programs by simply double clicking on one of its files. Like when someone double clicks on a TXT file it opens notepad. I'd like to be able to do the same. Thanks in advance for any help.

texasclubsi · Answer

Ok I figured out how associate a file type with a program but now I would like to know how to edit the commands passed to the program during startup. In other words how to execute code when the file is opened. Thanks.