Update another workbook without opening

Hello... there's really no great urgency here, but just as a little ui improvement I'd like to make a quick update to a workbook without having to open it. In other words, File 1 contains my user forms, data processing stuff, etc. When all the data is processed in File 1, I'd like to place a note in File 2 that confirms completion. I'm doing it now by opening File2, but am wondering if that's even necessary... can it be updated without being opened first?
I seem to recall that it can be done, but haven't had any luck with searches here or on google.

Thanks for any guidance!

See if this helps:

http://support.microsoft.com/default...;en-us;Q278973