Writing a macro to capture values on one spreadsheet and add them to totals on another spreadsheet that is out on the server.

[ghostbroker2]

Production Sheet dropbox link:
https://www.dropbox.com/s/vi2zpdo86euia3d/Production%20sheet%20%28TEST%29.xlsm?dl=0
Extrusion Tracking Dropbox link:
https://www.dropbox.com/s/5rn7wcsy62bupcl/Extrusion%20Tracking%20TEST.xlsx?dl=0
On the Production Sheet, cells K3 through K5 will contain scrap values. Cells I3 through I5 contain operators names in drop down menus.
I need totals from K3:K5 combined with values in column P on the Extrusion Tracking sheet. I need the total to go to the row with the corresponding name from the Production Sheet cells I3:I5.
The Extrusion tracking spreadsheet lives out on our server and is usually not open. The pathway is:
"\\RWCAD\Dashboards\Extrusion Tracking TEST.xlxs"
I'm still new to VBA and don't know how to pull this one off.
I've tried to modify a macro that you guys helped write for me, but no avail.
Here's what I tried, but not working.

Sub macSubmitScrap()
Dim W, wbSource As Workbook
Dim C As Range
Dim lngR As Long

Set wbSource = ActiveWorkbook
Set W = Application.Workbooks.Open("\\RWCAD\Dashboards\Extrusion Tracking TEST.xlsx")
Set C = W.Sheets(1).Range("B4:B15").Find(wbSource.Sheets(1).Range("I3").Value)

If C Is Nothing Then
MsgBox wbSource.Sheets(1).Range("I3").Value & " Was Not Found!"
Exit Sub
End If

lngR = C.Row

With W.Sheets(1).Cells(lngR, "P")
.Value = .Value + wbSource.Sheets(1).Range("K3").Value
End With
With W.Sheets(1).Cells(lngR, "P")
.Value = .Value + wbSource.Sheets(1).Range("K4").Value
End With
With W.Sheets(1).Cells(lngR, "P")
.Value = .Value + wbSource.Sheets(1).Range("K4").Value
End With

W.Close True

End Sub