No, there is no option to delete any particular restore point.
The only options you have are to delete all by turning Restore off (this you already know); delete all but the last by going to System Cleanup and on the More Option tab and in the System Restore section click the Cleanup Button and OK your way out.
There is a third, hit and miss, way to remove the oldest restore points. Go to the tab where you turn Restore on/off and reduce the amount of disk space allowed, As you reduce the disk space older restore points (oldest first) are deleted, but the only way you know that one or more have gone is to run restore and see what ones still exist in the "Calendar". If you reduce the storage space Restore will be turned off without warming! (200MB from memory). You may have to do this for each drive you have.
Geoff