That is an interesting problem and I think the right tool to use for it is the DATA step. Post this question at the SAS Discussion Forum
http://support.sas.com/forums/forum.jspa?forumID=31
and I'll wager you'll get a helpful response.

When you post your question, you should also specify if there are always four records for each ID, or if the number of records varies for each ID. If the number of records per ID varies, is there an upper bound on the number (like, less than 10)?

Good luck, and best wishes.