How do I set Transition Level?

[Timberleaf 1]

How do I set the Transition Level and Transition Altitude in FS2Crew? When flying in other countries, their TA and TL may be something other than 10,000'  and 18,000' (respectively); wherein the standard barometric pressure is set to 29.92 at 18,000' in USA, for example. How do I get FS2Crew to recognize a level other than 10,000' and 18,000', or have I an "understanding" challenge? Set me straight.

[Budbud 227]

The values are read out directly from the FMC, so just enter the transition altitude in the init page and the transition level in the desc forecast page.

The callouts will be done according to values in the FMC.