OUCH! Maybe its a shift cable? or the shift tower perhaps.
If you turn the steering wheel fully right and look through the left front wheel well at the trans you can see where the cables connect to the shift tower. Have someone move the stick around and you should see the cables moving the shift tower levers. If both aren't moving then its probably a broken cable. if both are moving then you can pull the shift tower and easily look inside the transmission to see whats up. Sounds like a cable or a tower to me though it is possible that it could be further in the transmission.

Good luck.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black