Nope.
Forget it, it can't be done unless you dismantle the iMac and fabricate your own monitor.
Sell the iMac on eBay as a broken machine, and buy a $150 - $200 LCD monitor.
Welcome to MR by the way. 2 things will help -- make your thread title relevant to your question, and try Searching the forums for similar questions first - we answer this one about once per month.