Hi Muthahar - this can definitely be done. I worked on a project where we used standard packages (rather than stored procedures) within the OTM workflow but I dont have the details to hand unfortunately.
You should probably refer to the Technical Consultant or the DBA that is involved on your project for the best advice on how to implement what you are looking to do (I seem to remember there were quite a few guidelines that our TC gave us when we did something similar).