This is quite easy: you want single letters between ':'s to be sorted as if they were without the ':'. As we're at it, we do a case-insensitive sort. That's the beauty of perl hashes! :-) 
use strict;

my %aq = map ( (lc ((/^:(.):/) ? $1 : $_) => $_) , <DATA>);
foreach my $k ( sort keys %aq ) { print $aq{$k}; }

__DATA__
D for Donkey
B for Box
B for Bubble
C for Cat 
A for Alpha
:A:
:B:
:C:
:D:

[download]
This stuff prints: 
:A:
A for Alpha
:B:
B for Box
B for Bubble
:C:
C for Cat
:D:
D for Donkey

[download]
Hope this is what you were looking for.

In reply to Re: Find by l3nz
in thread Creating a text index for a text file by texuser74

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