T9 with the phone

i have hindreds of contacts. i want to call "andrea". using t9 feature, i press 263732 and it automatically filter all the names where there is a string with first character is 2=[a,b,c] second is 6=[m,n,o] third is 3=[d,e,f] and so on... at the moment the user interface have number and letters, but the letters don't work...