How to specify relative path of wad file in settings.xml

First I set the Project Properties "Resource Root" to ${projectDir} to use it to reference files using a relative path.

I have a settings.xml in a service definition folder called "soapUiDemo" and want to to set the "definition_url" file to point to a "wadl" file that is located in the same directory. In the "Service Properties" panel the Base Path is set to:

C:\Users\me9417\Documents\NextGen\test project\soapUiDemo

and the WADL defined as:

C:\${projectDir}\soapuDemo.wadl

When I load the Service Properties and then click on the link to the WADL file path "WADL URL" nothing happens.
Not even an error. The file "soapuDemo.wadl" exists in the folder:

C:\Users\me9417\Documents\NextGen\test project\soapUiDemo\soapuDemo.wadl

If is specify the full path of the file in the settings.xml file is loads, works and can be clicked on and brings up Notepad with the file contents.

I'm attempting to make the reference to the wadl file and eventually xsds to be relative so othere could retreive the project from a source code control
system without changing a full path of the files. What am I doing incorrectly?