Start a process TopMost

I have a C# .Net 2.0 app which implements a FullscreenMode like this:

targetForm.WindowState = FormWindowState.Maximized;
targetForm.FormBorderStyle = FormBorderStyle.None;
targetForm.TopMost = true;
WinApi.SetWinFullScreen(targetForm.Handle); // let me know if you need the code of this methode

If the user is in FullscreenMode and tries to open the Help nothing happens(visible to the user), the开发者_Python百科 HelpWindow gets shown up behind my fullscreen form. The helpfile gets openend like this:

string helpPath= Registry.CurrentUser.OpenSubKey(@"Software\...").GetValue("HelpFile") as string;
System.Diagnostics.Process.Start(helpPath); // the helpfile is a *.chm file

Is it possible to start a Process TopMost or bring it in front of the invoking form? And if so, how?

I've been using the following code to bring the current window to the top:

    [DllImport("user32")]
    static extern int BringWindowToTop(int hwnd);

    BringWindowToTop(this.Handle.ToInt32());