simulating a mouse click

Declare Function SetCursorPos Lib "user32" (ByVal x _
As Long, ByVal y As Long) As Long
Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long

Type POINTAPI
    x As Long
    y As Long
End Type

Private Sub Command1_Click()
Dim P As POINTAPI
Dim t&, k$, y
For y = 0 To 500
Do: DoEvents
t& = SetCursorPos(300, y) 'SetCursorPos (x,y)
k$ = GetCursorPos(P)
Loop Until k$
Next
End Sub

Hope that helps.