Is there a strategy for keyword redirects for legacy products?

Summary: We are looking to sunset some products but because these products are included on marketing materials, there is a possibility that customers may try a link and we want to avoid them hitting a 404 page on the shop. The ideal would be for customers to be able to redirected to another external page, like our marketing site. How would we go about doing this through OCC so that the URLs don't result in dead links?

Content (required): How do you set up a keyword redirect OUT of OCC versus the out of box methods which redirect WITHIN OCC?

Version (include the version you are using, if applicable):