Iis Configuration To Set Web Site 'root' Directory

I have a web site for my business that I've developed inhouse, and is hosted offsite. I constantly need to access the data on the site (pricing, part numbers, etc). In order to not inflate the stats for the 'real' site, I keep my development server running 24/7. But, I thought that since I also have my WHS v1 server running 24/7, and since WHS is a web server, I thought I could move my inhouse development site onto it. One less computer running up the electric bill. But, I'm trying not to rewrite the site just so I can run it on WHS.

In IIS Manager, I created a virtual directory (let's call it <SiteName>) that points to the C:\Inetpub\<SiteName> folder. I copied all of the site files and subdirectories into this folder. From a browser, if I launch /Server/<SiteName>, the site loads. But, ...

I used a number of PHP includes (I do have PHP running on the WHS) and several levels of files and directorys. Since many common files are in the root directory, I used a lot of href="../<filename>" calls to specify that the file is indeed in the root directory. This is where I'm running into a problem.

Under IIS, each reference to "../<filename>" points to /Server/<filename>, not to /Server/<SiteName>/<filename>.

Is there any way to configure IIS to set the root directory *for this site* to be /Server/<SiteName>/, and not mess up the /Home and /Remote sites?

Thanks!

Malcolm