Program Change Midi -> New Tempo

Hey guys. I try to slave Reaper to my RC300 Looper (The RC300 has to be master). It all runs fine IF reaper has the same tempo like the RC300 but it does not change the tempo automatically. So I thought I could try it with the Program Change command because the tempo of the RC300 is fixed to every program. How can I configure Reaper to change TEMPO to *** IF it receives PROGRAM CHANGE *** (ReaControlMidi shows me it receives the PC command) Your help would be awesome!!! thanx

AS far as I know, Reaper can't be slave to an external MIDI device

Thats no problem - it runs! But I need to know how I can change the tempo via program change command!