Cap-exempt status for Expired H1B Petition, Visa stamped but unused

Hi,

 I am working for an employer "XYZ".  I have visa validity till August 2013.  I have never been to US  and not sure whether I will get a chance before August 2013 to travel.  I have heard about Cap Exempted H1B.  

Assuming that my visa expired. I have the following queries.

  1. Whenever next time If I want to get a H1B . Will I be able to get the cap exempted H1B only through my current employer “XYZ”?

  2. If I move to an employer “ABC”, Can employer “ABC” file a cap exempted H1B for me ?

  3. After how many weeks/months/years of my current visa expiry can I apply for cap exempted H1B.

Thanks.

1, 2. Cap-exempt petition can be filed either by XYZ or any other employer ABC

  1. This can be applied as early as now, and as late as within 6 years of original H-1 approval date