Editing the Right-Click menu in XP

[sheemone00]

I created a right click option for a file comparison tool by editing the registry. The problem I have now is that if I select multiple files to compare and use this new option it will open up two separate instances of the program and open the files separately.

Is there a simple solution to opening both files within the same instance of the program or do I have to resort to writing a script?

Thanks in advance.