Is there a sprinkler that I can restrict to a small rectangular area between two buildings?

Yes, an oscillating sprinkler can be set so that it will direct water to a specific area. There are also pattern sprinklers.

Check your state and local codes before starting any project. Follow all safety precautions. Information in this document has been furnished by the North American Retail Hardware Association (NRHA) and associated contributors. Every effort has been made to ensure accuracy and safety. Neither NRHA, any contributor nor the retailer can be held responsible for damages or injuries resulting from the use of the information in this document.