>>810-811
ちょっと余計なことを言ったかなと反省している。
SetTimerは使い方を間違えるととても危険なので、
仕組みが分からない人は使わないほうが良い。

Private Declare Function SetTimer Lib "user32" _
(ByVal hWnd As Long, _
ByVal nIDEvent As Long, _
ByVal uElapse As Long, _
ByVal lpTimerFunc As Long) As Long
Private Declare Function KillTimer Lib "user32" _
(ByVal hWnd As Long, _
ByVal nIDEvent As Long) As Long
Private rngTarget As Range
Public Function main()
Dim hWnd As Long
hWnd = Application.hWnd
Set rngTarget = ActiveCell
Call SetTimer(hWnd, 1, 100, AddressOf TimerProc)
End Function
Private Function TimerProc _
(ByVal hWnd As Long, _
ByVal msg As Long, _
ByVal wParam As Long, _
ByVal lParam As Long) As Long
Select Case wParam
Case 1
rngTarget.Value = ""
rngTarget.Interior.Color = vbRed
Call KillTimer(hWnd, 1)
End Select
End Function