get the current application using the assembly

[ireland]

I have and Windows Service and a couple of Web Applications all using the same assemblies.
When a call is made to one method in particular in one of these common assemblies I want to either pass it the current applications name or path or have the method itself determine what called it.
The reason being I have some System.Configuration stuff goin on within the method and if it's a Windows Service that called the method I want it to use the

System.Configuration.ConfigurationManager.OpenExeConfiguration(appnameandpath);

and if it's a website I want it to use the

System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(
                 "/websitename");

How can I achieve this?

The .config files contain some Custom Sections which I wish to access, I have no problem getting to the Web Applications but determining the Windows Service path and name and opening its app.config is proving difficult.

public static string GetMessageString(string server, string messagename)
        {
            string serverName = "/";
            string message = string.Empty;
            
            System.Configuration.Configuration configuration;
            MessageSection section;
            //Try the current Applications .config file first, if it exists, e.g. the ManagementServer.config
            try
            {
                configuration = System.Configuration.ConfigurationManager.OpenExeConfiguration(server);
                section = (MessageSection)configuration.GetSection("messagegroup/messagesection");
                message = section.GetMessage(messagename);

            }
            catch//if the exe's config fails then try the Web application web.config
            {
                configuration = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(
                 "/" + server);
                section = (MessageSection)configuration.GetSection("messagegroup/messagesection");
                message = section.GetMessage(messagename);
            
            }
                  
            return message;
        }