Need to modify VBA Code that copies multiple sheets to a master sheet

I found the code below and it works perfectly if I want to copy all the other sheets to a master sheet. But, I need to specify specific sheets. Basically I have a workbook consisting of multiple sheets and multiple "master" sheets so I need to specify in the code which sheets it should be copying.

Private Sub Worksheet_Activate()
Dim Sheet As Worksheet

For Each Sheet In Me.Parent.Sheets
    If Sheet.Name <> Me.Name Then
        If Sheet.Cells(Rows.Count, 1).End(xlUp).Row <> 1 Then
            Sheet.Range(Sheet.Cells(2, 1), Sheet.Cells(Sheet.Cells(Rows.Count, 1).End(xlUp).Row, 18)).Copy Destination:=Me.Cells(Rows.Count, 1).End(xlUp).Offset(1, 0)

        End If
    Else
        Me.Range(Cells(2, 1), Cells(Rows.Count, 18)).Clear
    End If

Next Sheet
End Sub

I have found this question asked before but never ran across any useful answers. I am an extreme rookie when it comes to VBA.
Any advise would be greatly appreciated.