add only histogrames

Dear Rooters,

          I have some root files having some histograms and ntuples .
          But i want to add only 3 histograms from all root files( having
same name)
          leaving everything else .
          Can anybody suggest ?

    Thanks

   Regards
    Navneet

-- 
*******************************************
Navneet Kumar
Research Scholar
Department Of Physics
Panjab University
Chandigarh-160014
****************************************
E-mail:  naviblustar_at_yahoo.co.in
               knavneet.pu_at_gmail.com
               nav_at_rcf.rhic.bnl.gov
Phone : 631-344-1152
             : 631-344-5268
******************************************