how to random a part of password in crunch?

[amrzxc]

i have drive in truecrypt

i have a 29 characters from password like 2a4574410d3c422a1968c1d64db41XXX

how i can get the last 3 with crunch word list in backtrack or any other tool

i want to make every characters possible in this last 3 characters

[leevai]

crunch 29 29 abcdefghijklmnopqrstuvwxyz0123456789 -t 2a4574410d3c422a1968c1d64db41@@@ -o passwordlist

meaning:
crunch needs to find a password with minimum 29 and maximum 29 characters containing alfabet and nummerics characters starting with 2a4574410d3c422a1968c1d64db41 and looking for the last 3 @@@. The filename with words is called passwordlist (-o). you can chose whatever name.
To locate your file use the LS command.
I guess this should be it if. ;-)

[leevai]

forgot to tell that you will have a large number of possibilitys but your password will be in the list. maybe you can check it with aircrack??