It's very likely that the motherboard is damaged. If you can, then repair it as suggested by Graham ®. Otherwise if the processor is fairly modern, you may be surprised at how cheap a new motherboard can be.
I am sure I killed a motherboard in much the same way, but by catching the solder joints beside the memory slot with the heatsink clip (memory slot too close to cpu slot anyway), have not had a good look at the board yet, just got another.
I was trying to do this with the motherboard in the case - in hindsight should have removed it
I bought this msi kt600 board off ebay - new oem - delivered for £22 - am well impressed with it.
Waiting on another msi kt400 new oem to arrive for £17.50 - same seller, great deals.
Your hard drive will work in a new motherboard of the same model. It will probably work in another motherboard using the same chipset. There is a very good chance that it will work well enough to back up any data if the chipset is different but by the same manufacturer (e.g.VIA). It may even work well enough to recover the data with a completely different chipset. The chances of success steadily diminish as you get away from the original chipset, but may be no worse than error messages and possibly no CD drives working until you reformat and clean reinstall.
BodgeItAndScarper, you don't always have to format your hard drives when installing a new mobo.
As long as you have all the drivers to hand you can just install the mobo and windows will ask for the drivers as the new hardware is found when you start the computer up, granted, it is not the ideal solution but I have done this myself on a few occasions to retrieve data.
If you buy exactly the same make/model of mobo you wont even have this problem.
BTW, if you have broken a trace on the mobo you could, as a last resort, try soldering it, or try rubbing the tip of a soft pencil over the break which can sometimes deposit enough graphite to "bridge" the gap and restore conductivity.