Apache RewriteMap with wildcard

We want to migrate multiple domains on new servers. In the first step (though from a SEO point of this is not recommendable) everything has to be redirected to the new domain's root. Later the team wants to have more fine grained redirects (thus the usage for RewriteMaps) I thought of using something like this: ^/(.*) https://www.newdomain.com/ But it seems I am on the wrong track