这个不是很难。
Option Explicit
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Const WM_SYSCOMMAND = &H112
Const SC_SCREENSAVE = &HF140&
Public Sub ScreenRun(ByVal hwnd As Long)
SendMessage hwnd, WM_SYSCOMMAND, SC_SCREENSAVE, 0
End Sub