In case this helps anyone else.... my webinars are for state government and attendees can type their organization name many different ways, depending on abbreviations, if they include the state first, etc. This makes it hard view a roster and determine how many from each or how many organizations served.
After downloading registration or attendee list to Excel, I copy the email column, rename the new column "Domain" and use search/replace to strip off the username text and @. (Search for *@ and leave "replace" field empty.) Then I can sort by domain and have the list grouped by organization.
Occasionally someone will use their personal email, but that's pretty rare. So this helps us when we need to track organizations.
And if we need to standardize the organization name in the spreadsheet, it's much faster to edit when we have them sorted together.