how could be calculate no.joinig and manpower person????

Hi Expert,

I have  requirement on webi where in user enter 0calmonth(interval-selection screen) and display the no. of joining person for last 12 month and include the current month. and no.of manpower last year with current month. Example like that below

User enter calmonth- april2013 to nov2013 so result wiil be come like

Company code     calday                  No.of joining person                           No.of Manpower

1000                   April13                   500 ( eg.May2012 to april2013)           200( only April2012 should be come)

2000                   May13                   600 (eg. June 2012 to May 2013)        300(only May2012 should be come)

300                     june 13                  700(eg.July 2012 to june 2013)           400(only June2012 should be come)

:                        :                                  :                                                                                             .

:                        :

:                        :

800                    Nov13                  1000 ( eg  Dec2012 to Nov 2013)       800(only december 2102 should be come)

So could you please advice me how to do

Note: Data is coming for infocube

Regards

Waseem