Regex/egrep matching numbers in brackets

Experts:

I don't know that regular expressions will ever be easy for me, so if one of you guru's could help out, I'd appreciate it.

I'm trying to match a line in our syslog, but I can't figure out how to match a number inside a bracket. This is what I'm trying to match.
"Jul 16 00:01:34 webseal1 xinetd[5465]: Reading included configuration file"

This works well enough for me, but doesn't wildcard the PID
egrep -i "xinetd\[5465\]: Reading" filename

This is what I've tried. Obviously I'm not getting it.
egrep -i "xinetd\[\[0-9\]\]: Reading" filename
egrep -i "xinetd\[0-9\]: Reading" filename
egrep -i "xinetd\[[:digit:]\]: Reading" filename

And many other variants. I've done much googling to no avail. Could someone help me out?
Thanks in advance

Try:

egrep -i 'xinetd\[[0-9]+\]: Reading' filename

Thanks much!