allendevans:

I've not found a "search and replace" command to replace the commas with "nothing", allowing direct numeric manipulation of the scalar variables.

Really?

$ cat t.pl
#/usr/bin/perl
use strict;
use warnings;
use feature ':5.10';

my $t = "1,234,567.89";
$t =~ s/,//g;
say $t;

$ perl t.pl
1234567.89
[download]

...roboticus

When your only tool is a hammer, all problems look like your thumb.