You can only import templates that have been exported by ProSelect. This is because ProSelect uses its own template structure which is mathematical and not the same as Photoshop's for example.

However If you have Photoshop based templates,  you do have the ability to add an Overlay Image, a feature built into the ProSelect Template Editor.  This allows the use of Photoshop templates within the program and is automatically carried through to High-Res Production also.

Please see this article "Using Photoshop Templates in ProSelect" for more information.