Changing “From” In Outlook 97′ 98′ 2000

I have a number of users (~20) that have several email accounts. The problem is that they need to send email “From” xxxx@0001.com, xxxx@0002.com and xxx@003.com (NO this is not a spam service! We have tech people that work for all 4 of our different divisions) and the changing the “From” field only changes the title and not the header information. These messages are being screened at the header level and are being rejected or are giving unwanted info to the person replying to their email. Is there any way to change the information without having to set up completely new profiles for each account (sometimes as many as 4 per person) and exit Outlook and open under a new profile?