Addons can't auto-cast something for you. That's automation. If the spell you want is off the global cooldown (using it doesn't cause everything to go on cooldown for 1-1.5 seconds) then you can just attach it to something else in a macro.
But... for you... You need a buff reminder addon. Some of them will bind what needs to be cast to the mousewheel, and cast each spell as you spin it. Out of combat, of course. Here are a few to look at. (I use Cork, but used to use SmartBuff years ago.)
http://www.wowinterface.com/download...0629-Cork.html
http://www.wowinterface.com/download...SmartBuff.html
http://www.wowinterface.com/download...Buffwatch.html
__________________
"You'd be surprised how many people violate this simple principle every day of their lives and try to fit square pegs into round holes, ignoring the clear reality that Things Are As They Are." -Benjamin Hoff,
The Tao of Pooh