Sadly, the answer is no. The GP editor does not allow you to change the path for the installation source.
The way to save yourself a headache in the future is to create a Distributed File System (DFS) structure and point to the installation files through DFS. You then create the GPO and set it to access the installation files via the DFS path. This way, if you want to move your installation files, all you have to do is change the DFS pointer!
