Can I setup different alert email profile, eg:
Ping plotter point to A area, then alert email send to A area administrator.
Ping plotter point to B area, then alert email send to B area administrator.

To do this, set up 2 different alerts - one for each of your administrators. Now, associate the proper alert to the proper target. Right-click the host you want to monitor and tie the proper alert to it (add/modify monitor option).

For specific details on setting up alerts, see the Alerts Tutorial. As outlined here, Ping Plotter requires you to pick which hosts you want to monitor - and which alerts you want tied to each one. One of the reasons for this is so you can do exactly what you're asking for. Feel free to follow up with more questions if this isn't clear.