Is this possible? I am using Excel 2003.

I have a list of all customers on worksheet named, Customers. Besides
listing customer demographics, it also includes a column to show which
company site services the customer.

The company needs to obtain further information regarding customers, which
is not demographic info. The company sites will enter this information. I
would like to have another worksheet for this purpose (I will name the
worksheet, OnCall Info). I will sent up columns to collect specific
information. I will include a column with data validation (list) for sites
to select customers from a drop down list (named range on customer
worksheet).

Since the company has over five-hundred customers, is it possible to filter
the drop down list based on the site selecting their location from a drop
down list (named worksheet range). I'm thinking I would have to require the
sites to select their location from a drop down list in a single cell on the
worksheet, OnCall Info. But how would I have the customer list show only
customers for that company site?

I don't have much experience with VBA. So if the above request would
require that, I would need help with writing the code.

TIA