Take a look at the counter commands in TCL. If all you want to do is increment a number by one and then add it to a message, this is one way to handle it.
CtrInitCounter
CtrNextValue
CtrCurrentValue
CtrResetValue
If you are new to TCL, this is a good one to write since it is relatively easy to code. Let me know if you need tcl code examples. The proc can be an inbound or xlt proc, depending on where you want to add the number.
