Polycom RMX 1500 Administrator's Manual page 1007

5
Optional. In the Description field, enter a description.
6 In the Target Regular Expression field enter ^ and the MCU prefix as
defined in the gatekeeper. This prefix is also defined in the RMX IP
Network Service.
For example, if 11 is the RMX prefix defined in gatekeeper, enter ^11.
The circumflex expression "^11" causes this route to be applied to all
numbers starting with "11".
Polycom RMX 1500/2000/4000 Administrator's Guide
H-21