outlook & profiles

We installed WinNT4.0 server as PDC. Then we created domain users to connect from existing W2K Pro PCs. The problem is that after the user has logged into domain with different name than it used to log on locally into w2k, their email is lost, because they were using MS Outlook 97, and I cannot find any *.pst files containing mail to import their exsiting mail. I see that w2k has created new profiles and old mail is lost. Does anyone know a solution?