Adding Presence Status with last activity

Hi all, I have customized spark by doing lots of changes to use it in my organization, but I am stuck with a single change what I want. I want to add the user info(last active time) of the person who is away or offline. I want this to be added in main window roster list. (As described in screen shot)

But I am not able to get the data from either dialogue box or tooltip window from where I can find the last activity of user.Can any one please help me with this ??

Waiting for an easy solution.

Please find the attached images for better understanding.