Thanks monks for your updates. They have been helpful. However still not working. I have restated my question for simplicity. 
@value = grep { /\b\w+\.\Q$domain\E/ } @DISKD;
@value = grep { /\b[A-Za-z1-9-]+\.\Q$domain\E/ } @DISKD;
@value = grep { /\b^(.*?)\.\Q$domain\E/ } @DISKD;

[download]
These entries match

hostname.foo.com
host1-name.foo.com
hostn124-name.somezone.foo.com
hostn122-name.otherzone.foo.com

All I want is the first two entries (hostname.foo.com and host1-name.foo.com). I have about 600 fully qualified domain names to scan through. Please let me know if there is some regex that will do this.... Thanks in advance!

In reply to Regex how to update by frank_2k4

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