Switching to an F1 while on an F1(OPT), with a pending H1B visa petition

Hi all, I'm in a rather complicated situation. I am currently on an F-1 visa with OPT, and I am working at a company. My company recently filed a petition sponsoring my H1-B visa. I wish to join school for a doctoral program this fall (Sep 2013) and I have admits already. However, I would need to switch to an F1 visa before beginning school. I don't want to quit my job before August. I'm confused of how I should proceed if I want to join school this September. My current F1 expires in June '13, and OPT expires in July '13. Any thoughts will be greatly appreciated.