ShowConflictHistory Property [Excel 2003 VBA Language Reference]
True if the Conflict History worksheet is visible in the workbook that's open as a shared list. Read/write Boolean.
If the specified workbook isn't open as a shared list, this property fails. To determine whether a workbook is open as a shared list, use the MultiUserEditing property.
This example determines whether the active workbook is open as a shared list. If it is, the example displays the Conflict History worksheet.
If ActiveWorkbook.MultiUserEditing Then ActiveWorkbook.ShowConflictHistory = True End If