Hi,
Not as such no; however there are some variables that are available from within an event-script, so if you define the event-option policy to execute an event script. The event script would then have access internally to a variable $hostname which would contain the hostname of the local routing-engine that the script is running on, or the script could make an RPC call to obtain the configured hostname of the device etc.
In a scenario where-by you wanted some other variable out of the system to be processed such as your example of the dhcp based ip address, then the script can make an RPC call to obtain that information and then parse the response to trigger what-ever actions are necessary etc.
Regards,
Andy