Macro as the value

Does anyone know how to escape SOAP UI from automatically updating a macro before a request? I have a scenario where I need to pass a macro as the value of a parameter and it keeps submitting null as SOAP UI is automatically replacing.

here is the snippet:
   
             
                  Image
                  ${FILE:16d9f05b3e6ece3e29ee89f455344da6.gif}
             
           

The value of media_url needs to be "${FILE:16d9f05b3e6ece3e29ee89f455344da6.gif}", so I need it to escape the "$"

Any ideas?

Thanks
-Chris