somehting like this?
1) make a rectangular selection the size you want the black to take up
2) change slection mode to subtract (or hold alt) and make little vertical selections removing bits from the main part, not too wide.
3) while still slected, get out the vertical single row marquee tool and change mode to subract and start clicking all over randomly.
4) edit>fill>black
5) cut out a bit for the bottom numbers, and stick in random numbers.
OR
if you want you can use the one i posted if it will work for you, i don't care.
i hope this is what your asking for, if not please be more specific.