How to search a user by name

Hello,

I am building a workflow to create a project from a request (created through InterAct).

I have the project sponsor available on the request, but as a string, not as a user reference, since this is information coming from the email parse.

Is there a way to get the user using the user's name? - similar to getuserbyemail function available.

Thanks in advance,

Christophe