Litmus Integration with Tokens

I use litmus because it provides some dimensions not offered by Marketo...

Our challenge is that the litmus analytics architecture makes it so that we 'should' create a new analytics code for each send.  We would rather use only one analytics tracking code than having to create a new code for every email send.

The good news is that we can tokenize the .js, and ideally, I'd like to add a variable that 'MUST' change for each send, sort of like UTM variables... any suggestions?

Thanks

ND