How to Consume BW Reports Programmatically?

Hi all,

I'm VERY new to BW and can't get the right information from SDN.

I need to develop an Excel document (using .NET that has BW data\report) that has the ability to refresh its data. I'm interested in the ways BW exposes services that can get reports/data? are there any web services?

I would be glad if someone can send some links or information regarding these topics it would be great.