HPS conversion help

I currently have a 400w hps light with a flimsy reflective hood. It is not a cooltube but my current grow requires constant cooling because alot of heat could potentially build up. I was wondering if possible could I do a little work with cpu fans and whatnot and contruct a crude self cooled apparatus?

http://www.htgsupply.com/growlights.asp?categoryID=1&subcategoryID=155&typeID=55

THat is the one I own which has detachable sides on the hood and could potentially be cut without the use of powerful tools.

Any help is much appreciated, thanks.

I made a cool tube out of the housing that came with my light, a piece of glass, 6" flexible ducts from lowes, and a $25 6" duct fan (also from lowes). It works great for me. Made a massive difference in my 2X4X6 grow cab. Without it temps were pushing 100, with it, the temp is a steady 80 degrees about 8 inches from my light, and 75 degrees in the cab. I attached a home made carbon filter on the end of it that helps the smell too. Oh, and I am also using a 400W HPS. Hope this helps. PM me and I can give send you some pics of what I did, if you want.

I switched to a 400w Philips MasterColor HPS- RetroWhite in my closet area, and have noticed significant heat reduction. I didn't run fans before and burned my plants a bit, this time still no fan and no burning with the plants as close to the CMH as they were the HPS... perhaps a little closer. I have no thermometer so I cannot give you an exact difference, but my open closet with the HPS was helping to heat my computer room and now I have to have the heater on with the CMH...

It is no doubt the temps are gonna be raging in that box I'm constructing so rather than buy an entire new hood and light, maybe sealing off the bottom of the light and placing a fan into the end of the reflector opposite the light socket. I am having a hard to conveying how it will actually looking but basically the fan with displace the air around the light through a carbon filter outside the box. Will this be enough or should I try place an actual tube around the light for a more efficient heat suction?