Pivot Table Connection String – How to hide it?

Hi

We have several pivot table reports (Excel 97) that we distribute to our users. The reports connect to an SQL Server 2000 database. Some of the reports use trusted connection (windows) and others use non-trusted (SQL login). These reports can easily be opened using VBA or in Excel 2007 to view the connection string (settings). How can we protect or hide these settings? (especially the username and password). Any help would be appreciated.

Thanks