Before you change your post for the 4th time (without being kind enough to say you edited it!
), allow me to point out that your modification is merely truncating the output of this alias by one "character" and not exactly solving the issue. As for this "issue" that you are trying to solve, there isn't really much of an issue with the alias, but more of how mIRC is treating $chr(173) as two characters when $chr(173) is used somewhere.
For example, while using your alias..
This will output $+($chr(173)) on v7.1
//chr . $chr(173)
This outputs $+($chr(32),$chr(194),$chr(173)) on v7.1, which we can see is not getting us anywhere useful.