You can try this one: Giga Password Generator, a simple way to generate customized wordlists . It is Crunch powered and it has some modes that allows you to add a mask before or / and after each line of your wordlist, the same way you want to do in your example. This script was originally made to run on Backtrack 3 Final, but if you want to run a similar task in Backtrack 4 you can just easily use Crunch which gives really nice results.
You can also make your own little script like this for example:
whereCode:while read line do echo $line$end done </path-to-your-input-file/$input > /path-to-your-output-file/$file
$end will be the mask you want to add after each line of your wordlist, like 123 in your example
$input will be the name of your original wordlist
$output will be the name of the modified wordlist, with 123 added after each line
I hope this helps.