How can I print a banner 96" long x 36" wide?

I prefer to print from Powerpoint but can copy and paste the data into a few other programs that I have access to (CAD, Word, etc). The printer (plotter actually) i'm using is an HP DesignJet 450C. It seems like the largest I can make the powerpoint slide is 56x36. I don't want to pay to have someone else do this, I'll change my format or print onto two pcs. of paper before I do that. Thanks in advance!