Hello J.Bonner,
Two potential solutions I can think of for your questions.
1. Install the SEPM on the Data Drive
If you install the SEPM to the data drive, the ..\SEPM\Inetpub\Content will be on the drive. This folder (and its subfolders) are where the SEPM keeps a local copy of the definitions. (It also keeps a copy in the database.) I assume this is the folder you are interested in moving.
2. Mount a partition as a NTFS folder
You could have a partition (I assume this is possible in a SAN, but I'm not real savy on SANs) dedicated to holding the SEPM's definitions. You could mount this partition to Windows as the folder C:\Program Files (x86)\Symatnec\Symantec Endpoint Protection Manager\Inetpub. As far as Windows is concerned, it's just another folder.
You would need to stop our SEPM service before touching this folder and copy all existing data into the new Inetpub folder before restarting the service.
The benefit of this solution is that you can still have the SEPM on the C: drive. The downside is it's definitly not supported (meaning we can't help you set this up.)
Hope this helps.
James