Using unused expired I-797

[pratz69]

I have Unused and Expired H1B Petition (Approved for 3 Years in 2009 CAP quota) filed by employer A. It is expired in Sep '12. Another employer B had also filed an H1B petition for me in 2009 cap and i had been working with that company for the past 3 years and have just transferred to a new employer in CA with a 3 year extension approval.

A new employer C wants to file a concurrent part-time H1B for me. Since the H1-B cap for the year 2013 has already been filled, can this new employer file for a New H1B with CAP 2013 Exempt by attaching the unused & expired Approved I797 document from 2009.

If yes, what would be the procedure for filing and how long will it take before I can start working with this employer?

Thank you.