With Filestar you can easily convert PPS to DOTM. Accessible directly in your right click menu for single or batch PPS processing. How to convert PPS to DOTM:
1. Download and install the latest version of Filestar. (https://filestar.com)
2. Right click on one or more PPS file(s) on your desktop and select Convert with Filestar.
Type "convert dotm" in the search box.
3. Press Run.