Don't make that mistake. Human resource will check your visa status if you apply for different position. If the position is well qualify to file for h1 then talk to your manager and ask him/her everything, you situation. You don't need to have opt to file for your h1 visa. There are plenty of H1 available so you can just file your H1 and get approve it with in 2 months period.

By the way, are you on status? what visa status r u on now if your opt expired?

Good Luck...