Private Function ShellAndWait(ByVal program_name As String, ByVal window_style As VbAppWinStyle) As Boolean
Dim process_id As Long
Dim process_handle As Long
Dim exitCode As Long

    ' Start the program.
    On Error GoTo ShellError
    process_id = Shell(program_name, window_style)
    On Error GoTo 0

    ' Hide.

    DoEvents

    ' Wait for the program to finish.
    ' Get the process handle.
    process_handle = OpenProcess(SYNCHRONIZE, 0, process_id)
    If process_handle <> 0 Then
        WaitForSingleObject process_handle, INFINITE

        GetExitCodeProcess process_handle, exitCode
        CloseHandle process_handle
    End If

    ' Reappear.
    MsgBox program_name & " exit code: " & exitCode, vbOKOnly
    ShellAndWait = (exitCode = 0)
    Exit Function

ShellError:
    MsgBox "Error starting task " & Err.Description, vbOKOnly Or vbExclamation, "Error"

    ShellAndWait = False
End Function