If I get you right, the problem lies in the habit to use ',' as thousand separator, like in 1,234,567.99.

Perl nows _ as such a separator, so s/,/_/g should already solves the issue.

UPDATE

Sorry, further tests showed that this doesn't work in strings only for literal numbers.

Just stick with s/,//g

  DB<123> $x="1,234,567.99"
 => "1,234,567.99"

  DB<124> $x =~ s/,//g
 => 2

  DB<125> sprintf('%.2f', $x);
 => "1234567.99"
[download]