Regex : select one number in document with many spaces

Regex : select one number in document with many spaces

Can I select the number 3433 in this example of generated file with so
many spaces that I can not control?
RESULTATS
Effectuées
le



:
06/09/2013
15:12:30
DES ANALYSES BIOLOGIQUES
3433 130906 / 3842
Dossier
N°






:
Please see the exemple in live here : http://regexr.com?368ko Thank you
for your help
Edit: The number 3343 could change from a file to an other but it will
have always the same position I'm using regex with php All what I tried
was very bad and gave no results :(
It's a pdf document that I transform with pdftotext function of xpdf and
so I must have that number which change from a pdf to an other
It's very bad positioned and I don't know how to capture it via Regex
best regards Amorino