Add option to user dropdown?

[high6]

I want to add an option to the dropdown when you click a users name. My guess is to do this I would have to modify the template. But what about doing an action?

I want to have only mods+ be able to see/use the option and I want it to move a user to a certain usergroup.

New to vbulletin mods so not sure what to do. I do want to try creating a vbulletin mod to do this though.