You could either:
set up a send to a new aux channel
put the reverb on the new aux channel
send the output of the aux channel to a new audio track
then record enable the new track and press record
2) turn the mix on the reverb up to 100% so only reverb is playing on the original track, then bounce the region (using Bounce In Place) to a new track. Make sure you keep the original region when you bounce.
Hope that helps!