[Spce-user] Best way to force gateway?

[Henk]

Hi,

Some of my customers are using cheap routes and I want to force them to 
take a predefined gateway. At the moment I'm using a prefix like 800 for 
this (this country-code doesn't exist).
The problem is, that while it's easy to select  the correct gateway, 
with a callee pattern like ^sip:800.* , the prices with prefix must 
exist, resulting in pricelists with destination patterns like 
^(80[0-2])?31800 if the gateway is used for routes without prefix and 
with prefix 800..802.
While working correctly, it's not exactly good for speed with lists 
 >40000 entries and going through multiple lists.

So my question, is there a better way to do this?

Regards,

Henk