my ($value) = ($row =~  /.*,(.*)/); # gets value after the last comma
if (looks_like_number($value))
{
    ($row =~ s/,[^,]*$//); # gets substring before the last comma
    # DO STUFF ...
}
# DO STUFF ...

##</code><code>##

my ($value) = ($row =~  /.*,(.*)/);
my ($val) = ($row =~ s/,[^,]*$//);