You can also do it this way.
$s = "\xe7abc\xe7";
$s =~ s[@{[chr 231]}][X]g;
print $s;
XabcX
Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller
If I understand your problem, I can solve it! Of course, the same can be said for you.