So now I get to learn by doing and replace the broken cable and screw....
Thankfully I live very close to Scooterworks and they had the spare parts on the shelf so I picked up the new parts (and a spare) on the way home from work.
There were a number of people interested in a step by step instructions on how to do this fix and was going to put something together until i found this: http://vespamaintenance.com/body/clcable/index.html

I followed these instructions and it worked perfectly!!
In the process however I learned several things that I think might be useful if you have never done this before
Adjusting the clutch cable:
The barrel part of the adjustment screw is attached to the threaded part, so to make the adjustment, you back the lock nut away from the hole in the engine case that the adjustment screw is screwed into then turn the adjustment barrel until properly adjusted, then tighten the lock nut back against the engine. (Not knowing this is how I broke the cable in the first place

Installing the new clutch cable:
When feeding the cable in from the top (where the clutch hand lever is) put the barrel into the slot in the lever before getting the cable too far in. I had to remove the lever to insert the barrel and there were a bunch of washers to keep track of in there.
Set the adjustment screw somewhere in the middle before tightening the cable and attaching the pinch barrel. I had to redo the pinch barrel 3 times, first time the cable was too slack so there was not enough adjustment so then I set the adjustment screw all the way into the engine and then i got the cable on too tight and couldnt add slack to it. Third time was the charm with the adjustment screw out a bit then i could add slack or tighten as needed.
Wear disposable gloves when dealing with grease.
My vise grips where too big! I managed, but had to struggle to get them in position to grab a hold of the cable where it came out of the adjustment screw. Also you dont need a 4th hand tool, all you need is a properly placed vice grip and good to go.
For you seasoned guys out there please chime in with any other wisdom or tell me where I am wrong and just got lucky!
Hope this helps!