Hi Philippe,
Excellent question, even though it took 5 months to answer. See the attached sample file (with four 'data only' files) and code that follows that has the following capabilities:
a. Count the number of open Excel Instances.
b. Identify All Open Workbooks in All Open Instances of Excel.
c. Close All Open Workbooks in All Open Instances of Excel except for the Workbook that is running the code. PERSONAL.xls or equivalent is closed in ALL Workbooks.
d. Close PERSONAL.XLS or equivalent in the current instance of Excel without asking and without saving.
e. Access the contents of an Excel File in another instance of Excel.
Lewis
Code follows in an Ordinary Code Module such as Module1:
Bookmarks