Give a password a word document with a macro

We want a C# project to give a password developer options of word document with macro. It must be a project that give a password to word document with a macro. It should ask the user for the password. This should be the only data to be received from the user. It should be a C# project. It should work in office 97 and above. As a result, the macro should not be opened without asking for a password.. The macro code is independent of the subject.