Add my app to the right mouse button menu..

Question

hi,
first post for me :D
I have a little question: is possible to add my app to the menu of the right button click of the mouse ?
Like the "open with..." ...
I'll explain it better:
I write an app that take a zipped file in input, un-zip it, modify a certain byte, save and re-zip it... i want to add the voice "modify it" (for example) in the menu that appair when I click with the right button of my mouse on every kind of file (maybe only on zip file is better).
Is this possible? I think that i need to ad some strings to the Register: correct?
than you very much,
David