Escaping $ in asserted XML Xpath Match

I have a number of assertions for XML content that have "$" in them.

Where I'm looking for #[((${CD67610 addMonth="2"} - @{Nxt Pymt Due Date}) / 86400000) round="ROUND,1"], soapUI is looking for #[(( - @{Nxt Pymt Due Date}) / 86400000) round="ROUND,1"].

It seems like soapUI NG Pro is substituting the null value of a perceived variable ${CD67610 addMonth="2"} for my text.  Is there a way to escape this?

Thank you for your help