Closing outside window with instr stuff

Can someone please tell me how to close a window if it has a certain string in it's title?

eg. If there is two windows opened called 'Go!Zilla Downloads' and 'My Downloads', theyd both close because they both have the string 'Downloads' in them.

Thx.

VB Code:

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
 
Private Const WM_CLOSE = &H10
 
Private Sub cmdCloseApp_Click()
Dim CloseIt As Long
CloseIt = FindWindow(vbNullString, "Caption Of Window To Be Closed")
PostMessage CloseIt, WM_CLOSE, CLng(0), CLng(0)
End Sub