Create Stored Procedure

Say i had a system table in that table i had dbo.user then format (dd,mm,yyyy) after that i had dbo.user_backup_ 10_12_2007,dbo.user_backup_ 10_13_2007,dbo.user_backup_ 10_14_2007,dbo.user_backup_ 10_15_2007,dbo.user_backup_ 10_16_2007

If i use the SQL command
SELECT * FROM paychexdb.dbo.sysobjects
WHERE name like 'users_backup_%' AND xtype = 'U'
AND name not in( SELECT Top 3 name FROM paychexdb.dbo.sysobjects
WHERE name like 'users_backup_%' AND xtype = 'U'
ORDER BY Name DESC)


results would be 10_12_2007,10_13_2007.

So i want to put those results in a backup file and keep top 3 which is 10_14,10_15,10_16. I want to create a store procedure that i can execute and do that for all my tables. this stored proc (sp) should first backup the table if it doesn't exist and then delete all but the most recent 3