Can someone give me any pointers?

I am working on an application that copies files from one server to another after a file has been updated. I am using the source code from the link below to send the files to the windows api.

http://www.vb-world.net/files/shfileop/

My problem is while a file is coping, my app is momentarly tied up waiting for the copy to finish before it continues running again. I am tring to make it so the app I am writing will continue to look for modified files even when one is being copied. Any ideas?