This is what i ended up using 
Dim p As New ProcessStartInfo
        p.FileName = "C:\Mach4Hobby\Mach4GUI.exe" 'Apostrophes in a file path? eek
        p.Arguments = " /p Mach4Router /o C:\Mach4Hobby\Subroutines\run.txt "
        p.WindowStyle = ProcessWindowStyle.Maximized 'can be hidden
        Process.Start(p)
I am guessing the DLL option might work better ??