How to use template filename as default filename

New documents are given a default filename of Untitled 1 (where 1 is a series number). How can Untitled be replaced with the template filename followed by series number if filename already exists in directory? (ie similar to MS Office.) I need to retain template filename, change extension (since new document is not a template) and save document to a new directory.

I notice the filename is displayed in File, Properties, General tab. If it isn’t standard functionality maybe someone can explain how to do it in a macro.

This is standard functionality in MS-Office, surely there is a LO solution.

Bump post.