Does anyone know how to do this reliably?

I have several Excel applications that presently create XML of data and Post
it to an ASP site. This has been working for about 10 years.

Now that I'm upgrading the site to ASP.NET MVC, I'm trying to change old ASP
files that were receiving the Excel requests, with WCF services and I'm not
able to get it to work.

I've tried the WCF Moniker system and that doesn't work.

Has anyone been able to call a WCF service from Excel 2003 or 2007 Windows?

Thanks,