You can use a variety of third party services, including Bloomberg, FactSet, etc via their built in Excel add-ins.
Even an etrade or other retail brokerage account will be able to handle that (on a real-time basis too!)
However, if you are looking for a completely non-paid service, Yahoo Finance should be able to handle it as well in a couple of ways:
Static: follow the instructions here: http://www.spreadsheetml.com/technicali ... ices.shtml
This is less robust and requires manual set up time but then afterwards, you can select Refresh All and everything will update.
Dynamic: a function (macro) can be created to replicate the functionality in the paid services. We are working on the finishing touches of such a macro in our next launch of our WST macros! Stay tuned!