Opening a workbook already open by another user

Hi,

Firstly thanks for the help I've already had, just have another question if I can be so cheeky.

The macro below copies data from 10 cells on the open workbook, opens a master workbook called 'test', pastes it into the next free row, saves 'test' , closes it and then clears out the cells from the original workbook so it can be done again. Problem is that as up to 30 people could be using the same 'test' workbook and there is the chance that it could be open already, is there any code that can be added to the current macro that would look to see if the workbook was already open then wait a few moments and try again if it found it so.

Current macro:

Sub openclosepastessaves()
'ThisWorkbook.Save
    Sheets("Gary").Select
    Range("B336:K336").Select
    Selection.Copy
    Workbooks.Open FileName:="C:\********\test.xls"
    'Sheets("Master").Select
    
    Count = 4
    Do
       Count = Count + 1
    Loop Until Sheets("Master").Cells(Count, 2).Formula = ""
    
    Sheets("Master").Cells(Count, 2).Select
    ActiveSheet.Paste
    Workbooks("test.xls").Activate
ActiveWorkbook.Save
ActiveWorkbook.Close
    Sheets("Gary").Select
    Range("D336").Select
    Selection.ClearContents
    Range("G336:K336").Select
    Selection.ClearContents
    Range("D336").Select
End Sub

Many thanks in advance