EXS 24 Logic Sampler Users Group

Hi!
Im' using cello (bowed) in a piece and I need some long notes. It happens that they are 
(shortly) too long and the sample loops from it's beginning during the last (few) milliseconds, 
so I hear the attack twice. In the "real word" if you play very piano the bow is long enough to 
allow this (the part will be played by a real player), but now the music has to be listened by 
my client, before it will "really" played. Which parameters should I use (eg, temporaly, like 
midi messages, or anything else) to allow long notes?
Thanks in advance

Gianfrancesco