Coping some selected attribute values from one workItem to another

Hi

I'm interested to know that is it possible to copy attribute values or auto populate date in one work item based on another work item in RTC.

Eg : I have two work items : Tasks, Stories

Both with a custom attribute called "Number of days". I manually enter a value to the "Number of days" field in task work item and what I would like to know is that, is there a way that I can get the same value auto populated in the Story workitem to the same "Number of days" field or to another field?

Thanks in advance for your help

DK