mIRC (typically) removes double spaces. This isn't going to change, and been brought up many times a year. Try using $replace(%Text, $chr(32), $chr(160)), it should show correctly to all mIRC clients (and perhaps other clients).
Using $chr(160) is a "dangerous" way of showing multiple spaces. The reason is that not all fonts display that as a space. Some fonts will display it as a block, which will really screw up how it looks. To avoid causing problems for some people, it's better to use spaces.dll or a ctrl code pairing. As long as you aren't going to have a really long line, this works very well. Personally, I avoid actually pairing them side-by-side except when I need to reduce spaces. For example, if I want 3 spaces, I'd put space,bold,space,bold,space. That allows you to have 3 spaces without using as many bold characters. You just need to make sure that you have an even number of bold characters. Note that you can also use Ctrl-R or Ctrl-U.
