How do I keep an instance unique? - excel

Question

In my work, I've made an workbook for my entire team to use, saved a macro in personal.xlsb to open it from anywhere in another instance of excel.
Its working fine by now, but I found a problem that i couldnt solve:
When the workbook is the last workbook open(when the first instance of excel is closed and left only the instance of my workbook), the next ones I open, start in the SAME instance of the workbook. (originally in instance 2) forcing me to run the code again to separate it.
Is there any way to protect that instance specially to the workbook itself?
sorry for my bad english.
Thanks
My code is:
Sub quickwb()
Dim NewExcel As Object
Set NewExcel = New Excel.Application
With NewExcel
.DisplayAlerts = False
.Visible = True
.Workbooks.Open "workbooknameandpath"
.DisplayAlerts = True
End With
End Sub

Answer 1

I'm not exactly sure what your issue is but below is a function I use to open a workbook if it's not already open.
Sub QuickWB()
On Error Resume Next
Dim wb As Workbook: Set wb = GetWorkBook("pathandbook")
If Not wb Is Nothing Then
' Do something
End If
End Sub
Public Function GetWorkBook(ByVal sFullName As String, Optional ReadOnly As Boolean) As Workbook
Dim sFile As String: sFile = Dir(sFullName)
On Error Resume Next
Set GetWorkBook = Workbooks(sFile)
If GetWorkBook Is Nothing Then Set GetWorkBook = Workbooks.Open(sFullName, ReadOnly:=ReadOnly)
On Error GoTo 0
End Function