Is it not possible to give them a rough estimate from the NPC on how long a given activity will take, then to throw complications and delays and requests for other team members to do things to help the hacker?
This is what I like doing. Takes less time than trying to look up and run the Matrix while the rest of the team is waiting for the hacker to open the door.
I mean I want to keep the game fun and flowing for everyone. If no one wants to play a hacker I'll just have to accept that. Forcing someone into the role is not the right way. I mean I want the group to have fun and be able to take on all the missions I throw at hem, but I dont want to slow things down further for everyone by adding another character to the 6 men group, even if it is an npc.
I think it can be done with some preparation and practice winging it - by the sound of it, you've already got a good grasp of what makes a fun time for your table anyway, so it's doubtful that either option will be disastrous.
The key - and everybody in the thread already seems to see this - is that you don't want to punish the players for liking the play style they've set up. It's
after they start making stupid decisions (in character) that you punish them - if they're trying to play a different game than you want to GM, then it's time for a sit-down out-of-character.
Otherwise, I think that the NPC hacker as a plot device is a great way to handle it - you don't have to make it too easy or hard, and you can have plenty of surprises come up at your whim without necessarily slamming the team.