From the program or patch that you are on...
1) hit your edit / insert key
2) select the Routing tab
3) use the BUS select to speciify which Bus you want to send this sound to...
your options are:
L/R - the main Audio outputs
IFX 1-5 - these can be used as MONO outputs - as 1.2.3.4 or as STEREO pairs as 1/2, 3/4

and hit exit key to get out...