my $dat = 'size="10">##ili22 234bvc 234yyyyy size="10">##ili33';
$dat =~ s/size="10"\>##ili(\d{1,2})/size="10" text-anchor="end">##ili$1/g;
print $dat;
#size="10" text-anchor="end">##ili22 234bvc 234yyyyy size="10" text-anchor="end">##ili33