You can expand your partitions but only in certain ways. For instance if your Windows partition is the first one, you can expand it into the second AFTER you erase the second. If I read your post correctly, you need to expand your SECOND partition into the first which I don't believe can be done. Here's the Apple article which explains how to do it.
http://docs.info.apple.com/article.html?path=DiskUtility/11.5/en/11491.html
Looks, like your best bet is to clone both partitions onto an external drive first, repartition your internal the way you want it, and reclone back onto it. In any case, I'd ALWAYS clone my partitions onto a backup drive first before trying to resize them.
Rick