How can I find the physical path of a web application from a web service?

[eunalp]

I'm working on a web service that will update the file content of a web application which is under the same server. The web service and the web application are independent from each other however the service will find the physical path of the web app and will overwrite the old files. The IIS tree is like this;

IIS
-----DefaultWebServi ces
-------------MyWebService
-------------------------App_Data
-------------------------updated file
-------------MyWebApp
-------------------------file
.
.
.

How can I find the physical path of the MyWebApp?
I will use this web service on many servers so the path differs from server to server.
I have searched and tried many solutions but they didn't work. I am using Csharp for that and need your help...
Thanks...