Obtaining the message ID set by the SMSC

Hi,

I would like to be able to get the message ID set by the SMSC. I know  
it is stored in the ts field int he DLR database. I have looked for a  
substitution variable to add it into the dlr-url but I can only find  
one for the internal kannel ID of the message. Have I missed it, or  
is it not possible?

Its very useful to get this ID for any issues / reconciliation with  
the operator.

Regards

Ben