The "DIRTY TRICK" for putting a drive side spoke is this:

1. Get the longest spoke you can find, probably 310mm
2. Find out your correct drive side spoke length, and mark this point on your long spoke.
3. Bend the spoke a hard ninety degrees at this point, then bend it back ninety leaving a kink a little wider then the hub flange thickness. It may take a little practice to get the bend at the right point.
4. Snip off the spoke a couple of mm past the final kink. You now have a spoke you can put in from the inside of the flange. This may not be ideal if you break an outer spoke, but remember: This is the stuff you do to get you home, not make a permanent repair. If you wanted a perm. repair you would have a little trailer with a tool box and trueing stand

P.S. You can bend the heck out of a spoke with out hurting it as long as you do not put a hard kink in it and then try to bend it back.