Try the following Technical Bulleting from Attachamte for more information: (you may have to log in as a guest)
Or here is the example from macro help:
"The example uses Shell to leave the current application and run the Calculator program included with Microsoft Windows. It uses the two Windows calls to find and minimize the Program Manager and EXTRA! Basic. It then returns EXTRA! Basic back to normal after prompting the user.
Declare Function ShowWindow Lib "User" (ByVal hWnd As Integer,
ByVal nCmdShow As Integer) As Integer
' The Declare statement above must appear on one line in your macro
' source code.
Declare Function FindWindow Lib "USER.EXE" (ByVal szClass$, ByVal
lpsz As Long) as Integer
' The Declare statement above must appear on one line in your macro
' source code.
Dim Hwnd as Integer
Sub Main
Hwnd% = FindWindow("progman",0) ' Find the Program Manager
x% = ShowWindow(Hwnd%,6) ' Minimize Program Manager
Hwnd% = FindWindow("EBFrameClass",0) ' Find EXTRA! Basic
x% = ShowWindow(Hwnd%,6) ' Minimize EXTRA! Basic
hWndCalc& = Shell("calc.exe", 1) ' Shell the calculator.
Msg$ = "Close the calculator and choose OK to return to EXTRA! Basic."
MsgBox Msg$
x% = ShowWindow(Hwnd%,1) ' Bring EXTRA! Basic back to
' normal size
End Sub