You need a named range in the external WB for your list source.

See Debra Dalgleish's site for instructions.

http://www.contextures.on.ca/xlDataVal05.html

Note: both workbooks must be open in order to select from dropdown.


Gord Dibben MS Excel MVP

On Tue, 27 Oct 2009 09:51:02 -0700, Dex
wrote:

I have followed the Office Assistant guidance but an error message appears
stating "you cannot reference cells in an external workbook". I couldn't make
sense of the online help information regarding this error and wonder if
anyone else can tell me how to get round it. Thanks.