During system register on RHN Satellite, how to execute custom scripts on it ?

Issue

• When the system is being registered on RHN Satellite, how to execute certain scripts automatically on that system ?
• With a mixed environment of machines created from a template, and machines created using kickstart, how to use Activation keys to perform execution of scripts (or snippets) so we can have a uniform view if the system is registered during kickstart or if it's registered using the bootstrap script ?
• How to use activation key for execution of scripts or remote commands ?