>>If you collapse the region, it's not going to search there.
>
>Unfortunately, it is not the case. This region gets expanded automatically when I do a search.

I haven't re-tried in VS 2010, but I'm quite positive that when I was searching within one page with collapsed regions in C# VS 2008, the search didn't check the collapsed regions. Perhaps there is an option affecting this behavior or it's different in VB.NET