The best way around this would be to create an Excel called 'launcher.xlsm' in the same folder as the file you wish to open. In the 'launcher' file put the following code in the 'Workbook' object, but set the constant TargetWBName to be the name of the file you wish to open.
Private Const TargetWBName As String = "myworkbook.xlsx"
'// First, a function to tell us if the workbook is already open...
Function WorkbookOpen(WorkBookName As String) As Boolean
' returns TRUE if the workbook is open
WorkbookOpen = False
On Error GoTo WorkBookNotOpen
If Len(Application.Workbooks(WorkBookName).Name) > 0 Then
WorkbookOpen = True
Exit Function
End If
WorkBookNotOpen:
End Function
Private Sub Workbook_Open()
'Check if our target workbook is open
If WorkbookOpen(TargetWBName) = False Then
'set calculation to manual
Application.Calculation = xlCalculationManual
Workbooks.Open ThisWorkbook.Path & "\" & TargetWBName
DoEvents
Me.Close False
End If
End Sub
Set the constant 'TargetWBName' to be the name of the workbook that you wish to open.
This code will simply switch calculation to manual, then open the file. The launcher file will then automatically close itself.
*NOTE: If you do not wish to be prompted to 'Enable Content' every time you open this file (depending on your security settings) you should temporarily remove the 'me.close' to prevent it from closing itself, save the file and set it to be trusted, and then re-enable the 'me.close' call before saving again. Alternatively, you could just set the False to True after Me.Close