comma in string replacement token

I've encountered an issue when using Copy File component and supplying the Source or Destination file path as a string replacement token.  When a filename contains a comma the comma seems to be interpreted as a break during substitution.  For example if a file name is "Test file, 2.txt" then the copy file component throws an error that file 'Test file' cannot be found.  The attached protocol has an example.

Is it possible to escape the comma in the global variable or string replacement token?  I tried adding quotes around the token in the Source parameter field but they get removed.

Thanks