here's an example that finds + moves an instance of notepad:

vb Code:
  1. Public Class Form1
  2.  
  3.     Private Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
  4.  
  5.     Const HWND_TOPMOST As Integer = -1
  6.     Const HWND_NOTOPMOST As Integer = -2
  7.     Const SWP_NOSIZE As Integer = &H1
  8.     Const SWP_NOACTIVATE As Integer = &H10
  9.     Const SWP_SHOWWINDOW As Integer = &H40
  10.  
  11.     Private Declare Sub SetWindowPos Lib "User32" (ByVal hWnd As IntPtr, ByVal hWndInsertAfter As Integer, ByVal X As Integer, ByVal Y As Integer, ByVal cx As Integer, ByVal cy As Integer, ByVal wFlags As Integer)
  12.  
  13.     Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  14.         Dim iHwnd As IntPtr = FindWindow("notepad", vbNullString)
  15.         SetWindowPos(iHwnd, HWND_TOPMOST, 100, 100, 0, 0, SWP_NOACTIVATE Or SWP_SHOWWINDOW Or SWP_NOSIZE)
  16.     End Sub
  17.  
  18. End Class