Restricting sms-service to a single number

[Kevin Dixon]

Hi, we have a Premium SMS service up and running AOK with our current set-up, which works in the following manner:
* User texts "66666" (obviously not the real number :-) with "TEXT" in the body as keyword.
* We receive through our gateway provider SMPP link, parse and send back a response via MT billed SMS to "66666", via the same SMPP link.

However, we are now in the process of expanding the Premium SMS services provided, with both other numbers and other keywords. What I can't seem to work out is how to ensure that an "sms-service" is only used for requests from a particular number. So, for instance, we'll have a service on "66666" and a service on "66667", and I want different "sms-service" groups to service each number (the keyword may be the same, and the requests come through the same SMPP link).
Example service from kannel.conf:

group = sms-service
name = GiveItService
keyword = TEXT
exec = /usr/local/SMSTool/smstool.sh -b '%a'  -t %Q  -f %q -i %I -u http://staging.server.com/inboundsms

Anyone know how to set up an "sms-service" restricted to only certain numbers/shortcodes? A trawl of the docs suggests only by keyword....

Thanks

Kevin