Can we add 2 more levels in PR release stategy

[kaukabr@yahoo.com]

Hello all Gurus:
I have senerio which needs to add two more levels in
Release strategy Purchase Requisition by using User
Exits. 
As SAP actually has only 8 levels cannot go beyond
this, and I have a requirement to add two more levels,
is this possible by using user exits if possible what
are the user exits. 
I hope any body might have some thoughts on this, I
will be appreciated.  

Many Thanks,
Regards,
Qhurram