Sum Several Workbooks

I've got a workbook for every department which is used to make a weekly status. Each of these workbooks contains a sheet with the 'weekly statuses over time', i.e. a table showing the weekly status for the department for week 1, week 2, week 3 etc. I've attached the file to make it easier to understand what I'm talking about, see Weekly_Test. Currently I can only see the performance of each department but I would like to be able to see the total performance for all departments, i.e. have a 'Total workbook' where all the weekly statuses are summed up weekly.

In the Weekly_Test file you can see the code which is used to generate the 'weekly status' sheets (also inserted at the end of this post). All workbooks for the departments are the same, apart from the file name which is the name of the department and this does not change. The weekly status is generated in the following way:

In the sheet 'Indtastning' (data entry) you enter the data and the date. Then click 'Update'. The sheet is then copied to a new sheet with the date and all data is copied to the table in the 'his.status' sheet. Now, I would like to add some code so that when I click 'Update' the data which is copied to the table in the 'his.status' sheet is also copied to a similar table in the 'Total' workbook.

Dim indtastArk
Dim arkDato
Public Sub Opdater()
arkDato = Cells(1, 1)

OpretDatoArk
' nulStilIndtastning
overførTilStatus
End Sub
Private Sub OpretDatoArk()
Sheets("Indtastning").Activate
With ActiveSheet
.Cells.Select
Selection.Copy
End With

ActiveWorkbook.Sheets.Add Before:=Sheets(4)......................