User has created accounts for some vendors in Core, but wants to use Employee Control to restrict their access to some modules. However, in the Employee Control screen, only the employees are listed on the grid and not vendors.
To see vendors on the Employee Control screen, you need to apply the Vendor filter in the screen and set the filter option to Yes. By default, only employees appear in drop-down lists or grids. Core lists the vendors on the screen and you can then set the Employee Control settings for them just like the employees. Check the Core Help for more on applying the filter in Employee Control.