Testing IP against a group of IPs

Does anybody out there have a simple solution to scanning a range of IP's against a user's IP?

Let's say I have a group of IP's

123.456.654.10/50

111.222.333.444.5/20

I need a script where I guess I could put in the min and max and scan for a match against the end users IP #remote_addr#

So I'd be looking at all IP's in the range:

123.456.654.10

to 123.456.654.50

And the

111.222.333.444.5

to

111.222.333.444.20

Appreciate any help

Thanks

Mark