3rd Party Access To My Forum/Database

[DJ RRebel]

I have one of my moderators who is really great at creating customised add-ons for my site. Now it's getting to the point where we'd like to link the add-ons to user info in the forum.

Things like verifying their password or reading/writting some data into a custom field.

I don't really have a problem with giving him access but I'd prefer it be done through his own seperate directory (on the same host).

My 3 main concerns for doing it this roundabout way is so that only I can actually hack/change/modify vB pages. (important to me because I like to document my changes AND that I want to do all such hacks myself so that I know they will be things I can redo myself if I ever have to upgrade and re-do the scripts when he's not availlable).

Is there any way for his php scripts to simply call a few 'includes' to actual vB php pages for his scripts to have access? Or is the only way to give him direct access to the database through my host's CPanel?