Depending on how much control you have over your data and the level of security, have you considered creating a security role called "Employees" and create a user for each staff and assign them to the new role? You can then use the standard user accounts module to search for your staff. The other way is to create a custom profile field and keep it invisible and in that profile field, just mark the newly created user as "staff" like a on/off flag.

---

Try our powerful shopping cart module for DotNetNuke!