After you've finished creating your template, when you click on <Save AS>,
At the bottom of the SaveAs window is a "Save As Type" box.
Expand that box and click on:
Template (*.xlt)
Name your template in the "File Name" box,
THEN click <Save>.
Now, to open a *copy* of the template that you can use,
Click <File> <New>
And you should find the name under the General tab.
Clicking on the template name opens a *copy* of the template, where you see
the name of the file with a "1" appended to the end of the name, which you
can fill in as needed, THEN <SAveAS> and RENAME before clicking on <Save>.
This procedure protects the original from revision and/or modification.
If the time arises where you must change or revise the original, just open a
copy as usual, make the changes, then *remove* the "1" from the end of the
name, and do the same thing you did when you originally created the
template, clicking on "Template (*.xlt)" in the "Save As Type" box.