mixing asp.net and Office OWC programming

Is there any practical way to mixing asp.net (server controls) and OWC (client, activeX) controls in aspx (code behind) pages?

For examples, can I have an asp.net tree control that, if you clicked on a node, would first call a webservice method to get xmldata, and then set a OWC pivot table's xmldata property to the fetched data?

samples would be great. Thanks everyone.A good source of answers is this forum:

http://dbforums.com/f191/

Also, check out the MSDN knowledge base article # 315695

Hope this helps.