Auto File Download

I am using VBA with MSAccess and the webbrowser control to download a file. I
have successfully done this numerous times when the download process is
initiated by a hyperlink, in which case, the url to the file is available
through the HRef property of the link. However, in this case, the process is
initiated by a button, which has no property that tells the URL of the file.
Clicking this button pops a modal dialog giving the options to save, open or
cancel. How can I get this file downloaded without the display of this dialog?

Thanks for any help
.