customer exit variables in bex should display in webi header

Hello gurus,

I created report in BW Query designer with restricted key figures like

1. current fiscal month sales value
2. Last fiscal month sales value
3. Current fiscal month last year sale value.

All the above months gets exectued based on customer exit

So lets say
current fiscal month = 11.2015
previous fiscal month = 10.2015
current fiscal month last year = 11.2014

Now in webi report my report header should display

current fiscal month/year = 11.2015
previous fisca month/year = 10.2015
current month last year = 11.2014

How can i achieve this?

thanks
Sri