Sorry for the long delay answering this, but no I don't know of any way to get Splunk's JSChart module or FlashChart module to do that. I was hoping someone else in the community would chime in if they had found a way, but I'm at a loss here.
What kind of chart is it? It might be possible to achieve the same goal with a little bit of Table Embedding... ie you could embed some simple HTML into a Table, or you could in theory embed JSChart modules into your table rows. Then you could have at least some immediately visible numbers in the table, and also have some visualization there too. Just a thought and obviously it depends greatly on your requirements.
It is a column chart. While generation report it comes with no indication of a exact value of the parameter. I had to say there is no functionality in splunk currently to the requesting party :(. Actually i was expecting some magic from you. I don't know how to embed the above suggestion to my implementation. Please guide me. Thanks.