[Refplace]

Mind Control and Possession both with Digital let you control a computer.
Mind Reading lets you read it while Mind Probe lets you sift through its data and Telesend (Telecommunication) lets you send your thoughts to it.
Special Rapport lets you know how its doing n a vague way.
MindLink lets you target it without having to see it.
Mind Shield would be a defense against most such things.
Data Jack is a version of Telecommunication that uses a cable to connect.
Finally Medium (Cybernetic) as suggested in Powers lets you talk to nearby computers and use influence skills on them.

I think that pretty much covers it, I have more I wrote for Pyramid that didnt get submitted in time that may someday see the light of day.
But similar ideas have been published, at least in Pyramid.

Personally cablejack or any telecommunication variant is valid for what you want, and I'd allow Medium as above as well.