No, its very much possible. Sorry, a lot going on and my support hasn't been the greatest lately.
Make sure you close RAT.
Then go to %appdata%\nomadsoft in Windows Explorer. Then copy the 7d2d_rat.db file. That's the entire DB for RAT.
On the new system, install RAT normally. Then just drop the .db file back in the same location on the new system, and start up RAT. You should be good to go.