Hi, Kevin. From what you've written, I understand that you have changed your "Code" settings so that PowerDesigner no longer switches the Code to upper case when converting your name property. If that's the case, you could run the script below. It is the equivalent of opening each Table and then clicking the "=" button next to the Code field. If you need to perform this task for other types of objects (References, Views, etc.), the same concept applies.
For Each oTable in ActiveModel.Tables
If you haven't run scripts before, just select Tools -> Execute Commands -> Edit/Run Script from the menu. Paste the script into the resulting window, and then click the Run button.