How to link Line chart to a calendar object

[onetwothree123]

I am having hard time linking a calendar object to a line chart.

Requirment is whenever user click on a date from calendar object,

corresponding line chart should display monthly avg.

Say user selects 05/24/2012 then line chart should display monthly avg. from 04/24/2012 to 05/24/12.

or say if user selects 06/20/2011 then line chart should be from 05/20/2011 to 06/20/2012

Data source is Excel where date is a column.

[onetwothree123]

Can anyone help me with this please