Add a custom field
 

I host support for a software company and I was want to have a required field that must be entered, What I am wanting is a field that a member must put in their software serial or put trial there whichever is the case. However I want to be able to see this as I'm the admin and want it only to be seen by a admin when looking at the persons registry info. Is there a way to do this?

This is to ensure there is no software piracy or a hack for the software in use.

You may not need a modification....

Admincp -> Custom Profile Fields -> Add New Profile Field

Type: Single Line Box
Field Required: Yes
Private Field: Yes

You can use regex to try and make sure something valid is entered.