Caller ID Variable

What is the variable to use caller id in an OGM.

For instance, have the message say "You are calling from 555-555-1212".

I figured it out the variable is cid, but I had to assign it to a local variable, and use that to make it work.

Now the problem is that the caller id is putting a 1 in front of the number, so that 5555551212, is read as 15555551212.

Is there some way to do a math function on a variable (ie. cid-10000000000) to get that 1 out of there?