Cant update data to closed workbook

OK,
Is there ANY WAY possible to update data in a closed Excel workbook ....by editing an opened workbook?
I have a mapping program that relies on info from an excel workbook to display. As info changes, I need to update it in Excel so it reflects in my mapping program.
Problem, if the map program is open, I cant edit the Excel workbook, it opens as a read only with a lock on it.. If the excel workbork is open, I cant update the map.
I need to update the data in Excel without opening it.
I have read a whole lot of posts saying it cant be done and some with complicated codes that strayed from the simple need I have.
Any ideas?

Hi

Only way I know of to update a closed workbook is to use an adodb connection to the workbook, and use sql to update / add data.

You do say that you have seen some with complicated codes... Do you have a link to those?

rylo