Extending viewlet (Work Items Statistics) with more params

I would really appreciate your help on the topic below, if possible for you.
I have a meeting with the customer today and need to know if this is possible:

Environment: RTC 1.0.1.1
Viewlet: Work Items Statistics (com.ibm.team.dashboard.viewlets.web.statistics)

This viewlet supports only specific parameters. The customer would like to extend this viewlet to consider additional parameters (i.e. "planned for" or other field), and of course the criteria for grouping the items within the pie chart.

Questions are:

1) Is it possible?
If so,
a) how?
b) where is this viewlet defined so I can take a look at the code?
c) can you point me to any specific documentation?

2) Is it recommended by Rational?
If not, which is the rationale of not recommending doing this?


Thanks in advance!