Private Sub Workbook_Open()
Dim maxWidth As Integer
Dim maxHeight As Integer
Application.WindowState = xlMaximized
maxWidth = Application.Width
maxHeight = Application.Height
Call CenterApp(maxWidth, maxHeight)
End Sub
Sub CenterApp(maxWidth As Integer, maxHeight As Integer)
Dim appLeft As Integer
Dim appTop As Integer
Dim appWidth As Integer
Dim appHeight As Integer
Application.WindowState = xlNormal
appLeft = maxWidth / 4
appTop = maxHeight / 4
appWidth = maxWidth / 2
appHeight = maxHeight / 2
Application.Left = appLeft
Application.Top = appTop
Application.Width = appWidth
Application.Height = appHeight
End Sub