Emulating asp.net FileUpload to work in all browsers

Question

I am writing an application that is used internally inside our network to upload data from an Excel spreadsheet into a database. I don't want to upload the file, but I want to allow the user to select a file from any location on a network.

I've built this to work fine using IE, but as many others have noted in their posts, other browsers don't allow access to a full file path.

I could just put a textbox, but then users would have to manually type in the path to the file.

Any ideas on how to take advantage of the FileUpload's built-in functionality but have it work across browsers?