[Render a subreport return param page wise]

I have a main report  which has an element X in the page footer  to be printed based on the subreport returned param Y.

Task :

In subreport  detail section page 1,  if an element occurs 10 times, element count '10' should be printed in the main report's  page 1 footer .

In subreport  detail section page 2,  if an element occurs 5 times, element count '5' should be printed in the main report's page 2 footer .

Issue :

I am passing a variable/param Y from subreport to main report , whose evaluation time is 'page'

When I display this subreport  passed variable Y  in the main report

Page 1 gives null

Page 2 gives 5 .

Is there any way that I can get the value 10 & 5 (multiple values page wise) from the subreport to main report ?

Thanks in advance,

Natyashree