Since your H1B petition expired in 2008, I presume it was approved in 2005 (usually H1B petitions are approved for 3 years, but depends on the duration applied and what USCIS think is right duration for the case). As far as I know, an H1B cap is valid for 6 years and in your case its over 6 years. I am not sure if you can use that petition for cap-exempt H1B transfer now. Please have this verified with a good immigration attorney.
If you happen to be eligible and got the H1B approval, I guess you can start working from the date of approval of COS (which you will have to file along with the H1B petition, if you are in the US) from L1 to H1B. If you are back in your home country, you can travel to US on stamped H1B.