Visa stamping in Spain

Dear Forum members:

I need to find out about extending my H1-B visa while on holiday in SPAIN. Here is a summary of my situation:

- I obtained H1-B visa approval and stamping in November 2007. My Visa was good to Nov 2009.

- I changed company in April 2009. My new company applied for H1-B transfer and extension. The approval (I-797A) came through this week. It carries an I94 with the name of the new company. The approval notice is now good through to April 2012.

- I had already booked a holiday in SPAIN and will be travelling in September.

My concern is my new approval (effective August 2009) invalidates my current Visa and I need to apply for a new Visa to re-enter the US. Can I apply while I am in SPAIN.

Look forward to your responses. Thanks