Organization Specific Fields

[Christian]

I am hoping someone may help me find a creative solution for a problem I am facing. There is a specific field in our JSM portal form that is currently an open short text field. We would like to make this a dropdown pick list, however certain items on the list need to be confidential based on the organization the portal customer is logging in with. As far as I know, it is not possible to make custom forms based on the organization of the user logged in (Please tell me if I am wrong about this). 

My other idea for a solution is to this is to have to agent select this field from a dropdown after this request is submitted, but I would need to ensure the items in that dropdown remain confidential from the customer. Is this possible?

Any other solutions are welcome. My preference would be to not add a plugin to do this, but if there is one that perfectly solves this problem I would be open to using it. 

Thank you for your help!

Christian