When designing the report:
- Open up a text box properties window
- Go to Navigation
- Enable Jump to URL
In the URL enter javascript:void(window.open( 'http://www.microsoft.com', '_blank')
Please note that you should replace the http://www.microsoft.com/ with the URL you would like to launch. Also note, that the second parameter of '_blank' is the standard window.open target meaning a new window.
Note: To make this to work in SQL Reporting services 2000 (especially opening in a new window) you need to install Hotfix for SQL Server 2000 Reporting Services SP2 and make sure you already have installed Reporting Services SP2, The hot fix setup will not run on computer unless you have SP2 Installed on your computer.