RE: Where are the Business Portal Users stored.
Hello Bill,
You mentioned you're "not moving to a new server or updating BP, we have to change the Company pointer for all the users already in an active Business Portal setting".
By 'Company pointer' are you referring to the company ID value from one company to another?
Ideally, if I understand what you're doing correctly, you'll want to do what Rob mentioned and after this new company is added to the SY01500 table (Company Master), run SQL Configuration for Business Portal, which will see this new company database and add it to Business Portal like we'd normally do. You'll also need to add Web Services to this new company database, depending on what version of Business Portal and SharePoint are being used.
Once that is done, then you can add the users back and use the MBFUser, MBFRole and MBFRoleUser tables in DYNAMICS to re-create the same MBF Roles the users are assigned in the original company database to the new one.
The SharePoint group information isn't company specific, so you won't need to add the users back to those groups as they should already be there.
This would be the supported process that we would recommend.
Thanks,