You can protect your vba code by setting the password.
Open your template (.dot file) in word.
To set the password, open the vba editor by pressing Alt + F11;
Goto Tools -> [project Name] properties
here the project name will be the your project name.
it will open a project properties window there will be two tabs General and protection.
Goto protection tab,
Check the option "Lock project for viewing"
Enter your desire password