Yes IT is possible. In many ways.
One create cluster for this ext and route and trunk.
Remember to add default cluster to clusters to include.
Btw I think I new releases clusters are called multitenant
second way is to make route which match callerid
for example _0X./5432
this route will match extension 5432
And third way
use search on this forum or on voip-info.org becouse the same topic were here approx 2month ago.
Realy use search becouse it is really possible next answer will be RTFM !!!!