in reply to Regex: If not beginning of string match end

Really, I don't know how your data looks like or how you are getting it..
However, does something like this work for you: 

use strict;
use warnings;

while(<DATA>){
 chomp;
   print $_,$/ if /\d{2}$/;
}

__DATA__
PHY/99/3006
PHY/99/3009
PHY/99/2678
PHY/99/390O
PHY/99/129R
PHY/99/UY90

[download]
Update
Output: 
PHY/99/3006
PHY/99/3009
PHY/99/2678
PHY/99/UY90

[download]

You can also check this Simple word matching

If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me

In Section Seekers of Perl Wisdom