howcan i pass a variable as a uri

Question

using the code below i need to be able to pass different server names into the URI dynamically. is there a way to do that? i have tried to pass it as a string and i get the error listed below. i also tried to pass it as a uri and that also errors. If i hard code @"\myserver" into theNetCache.Add(new Uri(@"\myserver"), "Basic", theNetworkCredential); it works. I cant have it hard coded since i need to be able to dynamically create the server on the go.

Uri relativeUri = new Uri(@"\myserver", UriKind.Relative);
string url =@"\myserver";



            NetworkCredential theNetworkCredential = new NetworkCredential(username, password);
    
            CredentialCache theNetCache = new CredentialCache();
            theNetCache.Add(new Uri(url), "Basic", theNetworkCredential);

System.UriFormatException HResult=0x80131537 Message=Invalid URI: The format of the URI could not be determined. Source=test PDF
StackTrace: at test_PDF.openPDF.showPDF() in C:\Code\test PDF\test PDF\openPDF.aspx.cs:line 44 at test_PDF.openPDF.btnTest_Click(Object sender, EventArgs e) in C:\Code\test PDF\test PDF\openPDF.aspx.cs:line 146