'Funktionsdefinition API-Aufruf für Session-Daten auslesen
    <DllImport("wtsapi32", CharSet:=CharSet.Ansi)> _
    Public Function WTSQuerySessionInformation( _
     ByVal hServer As Int32, _
     ByVal SessionId As Int32, _
     ByVal InfoClass As WTSInfoClass, _
     ByRef ppBuffer As IntPtr, _
     ByRef pCount As Int32) As Int32
    End Function
 
 
    'Funktionsdefinition für API-Aufruf "Speicher freigeben",
    <DllImport("wtsapi32", ExactSpelling:=True, SetLastError:=False)> _
    Private Sub WTSFreeMemory(ByVal pMemory As IntPtr)
 
    End Sub
 
    'String API's
    <DllImport("kernel32", EntryPoint:="lstrcpyA", SetLastError:=True, _
      CharSet:=CharSet.Ansi)> _
    Private Function StrCopyA(ByVal retval As String, ByVal Ptr As IntPtr) As _
    Int32
 
    End Function
 
    <DllImport("kernel32", EntryPoint:="lstrlenA", SetLastError:=True, _
      CharSet:=CharSet.Ansi)> _
    Private Function StrLenA(ByVal Ptr As IntPtr) As Int32
 
    End Function

Public Function GetWTSQueryHost(ByVal SessionID As Int32) As String
        Dim retval As Int32
        Dim lpBuffer As Int32
 
        Dim Count As Int32
        Dim lName As Int32
        Dim sName As String = ""
 
        Try
 
 
            'Remotesitzungsinformationen holen
            retval = WTSQuerySessionInformation(WTS_CURRENT_SERVER_HANDLE, _
                SessionID, WTSInfoClass.WTSClientName, lpBuffer, Count)
 
            'Funktionsausschnitt
            ' Prozedur erfolgreich
            If retval Then
 
                'Stringlänge ermitteln
                lName = StrLenA(lpBuffer)
 
                If lName <> 0 Then
 
                    'String initialisieren
                    sName = New String(" ", lName)
                    'String kopieren
                    Call StrCopyA(sName, lpBuffer)
                End If
 
                ' Speicher wieder freigeben
                WTSFreeMemory(lpBuffer)
            Else ....