I run a small company and have a large number of customers. I have made all customer related stuff in Excel (e.g. Invoices). Those are divided into separate functional Workbooks. The customer contacts are in its own Workbook (CUSTOMERS.xlsx) and used by every Workbook in the project.
In each application (Workbook) I need to get the customer from the customer workbook.
I have tested:
On opening a Workbook app I copy the most recent customer list from CUSTOMERS.XLSX to the workbook and use DGET to retrieve the correct record from the copied customer list. However, DGET loses the connection to the customer range/table name every time I update the list. The DGET function looks like

=DGET(tCUSTOMERS[ALL#];B1;$A1:$R2),
where tCUSTOMERS is the table I have just copied.

Can I use SQL instead to retrieve one specific record from the customer list in the closed CUSTOMERS.xlsx?
Probably easily, but I havent so far found any example on the net. Thankful for any advice.

/HÃ¥kan