add a macro to add a string to custom property

i would simply like to add \\\$prp:"Description" to the Description property which is always blank.  We use the configuration property

when i use the templat i can only add a text string. i cant add something that references another PRP.

 

is there a way to do this?

i just need to start the macro when a part is only and replace the custom propery for Description is the \\\$PRP:"Description"

 

thanks

Tim