Thank you. That prints to STDOUT very nicely. So one problem resolved.
But it doesn't solve the original problem. Here's a worked example.
When I parse my two "authoritative" spreadsheets of names of palearctic birds, I would hope that both authorities would have the same common name for the species whose latin binomial is Phoenicurus erythrogastrus
But they dont.
One calls it Güldenstädt's Redstart
The other Güldenstädt’s Redstart
(That's the difference between 0027;APOSTROPHE; and 2019;RIGHT SINGLE QUOTATION MARK (fide C:\Perl\lib\unicore\UnicodeData.txt))
My current solution is to do a s/// on each $string from each OOorg spreadsheet, as follows

  $string =~ s/(\P{InBasic_Latin})/                 # Look for codepoi
+nts that are not in Basic_Latin; for example the sign ü
    defined( $subs{ord($1)} )                       # if $1 = ü,  the
+n ord($1)  = 252. We ask is there a value in %subs for key '251' ?
     ?  $subs{ord($1)}                              # If yes ( $subs{2
+51} = û ), then return û
     : ' <$subs{'                                   # if no, then retu
+rn<$hash{ ...
       . ord($1)                                    #  252  ...
       . "} = ${charinfo(ord($1))}{name};> "        #  } = LATIN SMALL
+ LETTER U WITH DIAERESIS;>
                                    /egx;           # /egx = e execute
+ g repeated x spaced out regex
                                                    # If a sigle was f
+ound that is absent from the hash, then the outfile will contain  "<$
+subs{8224} = DAGGER;>" etc
                                                    # You have to writ
+e into make_the_subs_hash()  a line like this $subs{8224} = '¦'; . Th
+ats  at [1] below
                                                    # Then re run the 
+script with the extended  %subs
  return($string);
[download]

Where the hash %subs is made as follows

  foreach my $i (126 ... 255) {
      $subs{$i} = chr($i);
  }
  # Plus higher value code points found empirically; see [1] above
  $subs{338}  = 'OE';# LATIN CAPITAL LIGATURE OE
  $subs{339}  = 'oe';# LATIN SMALL LIGATURE OE
  $subs{8217} = "'" ;# RIGHT SINGLE QUOTATION MARK
  $subs{8224} = '×' ;# DAGGER
[download]

Ugly, but at least everyone can see what is going on
Richard H