Receiving error Cannot resolve URL when trying to run report in Rational Publishing Engine

I had to make an update to an existing report.  I took the original dta file and saved as DR_Failures_test.dta so I could make my updates and test.  In my original dta file the individual who created the report (he is no longer with the company) setup the URL so the report could be used globally across projects.  The URL he set was using a variable

${public}/rpt/repository/workitem?fields=workitem/workitem[projectArea/itemid=${projectAreaUUID}/(this request URL is appended with the correct display values returned.

I created a report resource using the original failure.dta file and the report is running via the web browser.  However if I use the original dta file and try to run it in the RPE Studio using Generate configure and and generate document and input the above URL in the Configure the data Resources the generation aborts because it cannot resolve the URL listed above.  I am not sure where the $public was defined, my problem is I cannot upload a new dta file with new changes until I can figure out how to get the report configured to use the above URL otherwise I will break the current report running when I upload a new dta to the report resource. Can you tell me where this $public would be set where it would be able to access path above in RPE?

RPE 1.2.1