Hi everyone, I found this almost perfect working code, except for one thing: when I've another workbook open, it gives an error at this line:

Set oXLws = oXLwb.Sheets("Overview")
Would it be possible to make this work without errors when I've already opened several other workbooks?
Here's the full code:
Const xlUp As Long = -4162
Sub ExportToExcel(MyMail As MailItem)
    Dim strID As String, olNS As Outlook.NameSpace
    Dim olMail As Outlook.MailItem
    Dim strFileName As String
    '~~> Excel Variables
    Dim oXLApp As Object, oXLwb As Object, oXLws As Object
    Dim lRow As Long
    strID = MyMail.EntryID
    Set olNS = Application.GetNamespace("MAPI")
    Set olMail = olNS.GetItemFromID(strID)
    '~~> Establish an EXCEL application object
    On Error Resume Next
    Set oXLApp = GetObject(, "Excel.Application")
    '~~> If not found then create new instance
    If Err.Number <> 0 Then
        Set oXLApp = CreateObject("Excel.Application")
    End If
    Err.Clear
    On Error GoTo 0
    '~~> Show Excel
    oXLApp.Visible = True
    '~~> Open the relevant file
    Set oXLwb = oXLApp.Workbooks.Open("C:\  HERE'S THE LOCATION")
    oXLwb.Activate
    On Error Resume Next
    Set oXLws = oXLwb.Sheets("Overview")
    
    '~~> Set the relevant output sheet. Change as applicable
    On Error Resume Next
    
    lRow = oXLwb.Sheets("Overview").Range("E" & oXLApp.Rows.Count).End(xlUp).Row + 1
    '~~> Write to outlook
    With oXLwb.Sheets("Overview")
        '
        '~~> Code here to output data from email to Excel File
        '~~> For example
        '
        .Range("D" & lRow).Value = (Now)
        .Range("E" & lRow).Value = olMail.Subject
        .Range("G" & lRow).Value = olMail.Body
        '
    End With
    '~~> Close and Clean up Excel
    'oXLwb.Close (True)
    'oXLApp.Quit
    Set oXLws = Nothing
    Set oXLwb = Nothing
    Set oXLApp = Nothing
    Set olMail = Nothing
    Set olNS = Nothing
End Sub
Thanks!