If you are using the standard incoident process, then take a look at Declaring a major incident and then the bit that does Add affected User. This has most of what you want.
I've implemented this using 'dummy windows', copy rules and the 'Create Child Incident' action, e.g.
Create an action called 'Clone Incident'
associate it with a 'Dummy Window' - in my example, I've used Copy Rules to copy the Summary and Description as these vary slightly from Incident to Incident. But you'll also see I've given the opportunity to enter a new Requestor and PC Name (we call it 'Config Item'):
Once you've entered a 'User' and 'Config Item' (and possibly amended the Summary & Desc), use an automatic action to save the details, then use an automatic instance of 'Create Child Incident' action to create a clone.
Really helpful guide on Dummy Windows and automatic actions here : http://community.landesk.com/support/docs/DOC-23866
It's complicated stuff but once you get your head around it, you'll wonder how you survived without cloning