Will Redirect Plugin help if my page has been renamed?

Hi,

I have now found out that an important page should be in its own directory.

But it was built outside of WP in an html editor.

And I have been putting a few links out to the world to the old URL.

Will a WP Redirect plugin work? (as the old page won’t be there, the 404 or whatever error will be within WP)

If not, what is the best way to do it please?

thanks a lot