Highland Avenue continues down the road to its mixed-use destiny, as yet another residential-retail complex is headed to underutilized blocks south of Hollywood Boulevard.  The latest project, intended for a set of parcels at 1233 N. Highland Avenue, would include 72 apartment units above ground floor commercial space.  The mixed-use development is located one block south of a similar project from the Miami-based Lennar Corporation, which will create 76 residential units and 2,500 square feet of street level retail space near Hollywood High School.  Further north, Champion Real Estate Company plans to break ground next year on a mixed-use development at the intersection of Highland and Selma Avenues.  Consisting of two six-story buildings, the project will create a total of 248 apartment dwellings, 13,000 square feet of ground floor commercial space.  The project will also lease approximately 35,000 square feet of office/industrial space to the Musician's Institute and Panavision.