Activating opened Excel workbook from Outlook - excel

Question

I have a macro in my Outlook that whenever I receive an e-mail with a certain subject, it automatically opens an Excel workbook and pastes a portion of the e-mail subject in a specific cell in one of the worksheets. It works perfectly. Now I need to do this exact same process but pasting this information in an already opened workbook, instead of opening a closed file.
I've tried different solutions from my limited Excel VBA knowledge (ActiveWorkbook, worbooks(filename).activate, etc.) but none of that worked and I have not found anything similar online, as most macros are written as being run from an Excel file and not Outlook.
This is part of our current code, that opens the file and pastes the e-mail subject (which is the "ticker" value) in a specific cell on the "Lista Empresas" worksheet. What I need is a code that does the same, but in an workbook that is already opened (let's call it "test1").
Dim exapp As Excel.Application
Dim ExWbk As Workbook
Dim ExWbk2 As Workbook
Set exapp = New Excel.Application
Set ExWbk2 = exapp.Workbooks.Open("\\XXX\ListaEmpresas_ajustado.xlsm", UpdateLinks:=0)
exapp.Visible = True
ExWbk2.Sheets("Lista Empresas").Range("P2").Value = ticker
ExWbk2.Sheets("Lista Empresas").Range("P3").Calculate

Answer 1

There are a few scenarios to handle here. First, is Excel running? If no, then do what you are doing already. If yes - is the correct workbook open? If yes - return it, otherwise open it.
Dim ExWbk2 As Workbook
Dim wb As Workbook
Dim exapp As Excel.Application
On Error Resume Next
Set exapp = GetObject(, "Excel.Application")
If Err.Number <> 0 Then
Set exapp = Nothing
End If
On Error GoTo 0
If exapp Is Nothing Then
' Excel is not running
Set exapp = New Excel.Application
Set ExWbk2 = exapp.Workbooks.Open("\\XXX\ListaEmpresas_ajustado.xlsm", UpdateLinks:=0)
ExWbk2.Visible = True
Else
' Excel is running, but is the right book open?
For Each wb In exapp.Workbooks
Debug.Print wb.Name ' <-- This will help you find what to look for
If wb.Name = "ListaEmpresas_ajustado" Then
' Yes, it is!
Set ExWbk2 = wb
End If
Next
If ExWbk2 Is Nothing Then
' No, it wasn't
Set ExWbk2 = exapp.Workbooks.Open("\\XXX\ListaEmpresas_ajustado.xlsm", UpdateLinks:=0)
End If
End If
The trick to find out if Excel is running is GetObject. It will fail if it can't find it.
The for loop is there to allow for finding the correct workbook, based on the name. Adjust as needed.

Answer 2

The following code gets the object if you know the name of the sheet currently active in Excel instance. I guess this could be got from the application title using the first bit of code.
Dim exapp As Excel.Application
Dim ExWbk As Workbook
Dim ExWbk2 As Workbook
Set exapp = GetObject("ListaEmpresas_ajustado.xlsm").Application
exapp.Visible = True
ExWbk2.Sheets("Lista Empresas").Range("P2").Value = ticker
ExWbk2.Sheets("Lista Empresas").Range("P3").Calculate