If you're more comfortable working inside Excel/VBA, use the open event and test the environment: either have a signal file, a registry entry or an environment variable that controls what the open event does.
You can create the file/setting outside and test inside (use GetEnviromentVariable for env-vars) and test easily. I've written VBScript but the similarities to VBA cause me more angst than ease..
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As I understand the problem, you want to use a spreadsheet normally most/some of the time yet have it run in batch and do something extra/different. You can open the sheet from the excel.exe command line but you can't control what it does unless it knows where it is. Using an environment variable is relatively simple and makes testing the spreadsheet easy.
To clarify, use the function below to examine the environment. In a module declare:
Private Declare Function GetEnvVar Lib "kernel32" Alias "GetEnvironmentVariableA" _
(ByVal lpName As String, ByVal lpBuffer As String, ByVal nSize As Long) As Long
Function GetEnvironmentVariable(var As String) As String
Dim numChars As Long
GetEnvironmentVariable = String(255, " ")
numChars = GetEnvVar(var, GetEnvironmentVariable, 255)
End Function
In the Workbook open event (as others):
Private Sub Workbook_Open()
If GetEnvironmentVariable("InBatch") = "TRUE" Then
Debug.Print "Batch"
Else
Debug.Print "Normal"
End If
End Sub
Add in active code as applicable. In the batch file, use
set InBatch=TRUE