I have a spreadsheet with filtering that is accessed on the internet by users
who can filter on diff columns to get to the specific data they need. From
there, they can click on diff hyperlinks.

How do I get the links to open in a new IE window?
or
If one IE window, how can I get their previous filtered selections to stay
when they use the back button?

The spreadsheet has many, many hyperlinks and is maintained by the user group.

Using IE 6.0 and Excel 2003 (corp rollout, so changing settings is not an
option).