As other have pointed out, you should generally use the correct type of quoting.

But, if you're just using hard-coded paths, you can skip the fancy quotes if you switch to unix-style paths. In other words, change the assignment to $binpath="c:/qa/kontor/bin";. As mentioned in this very old post, paths are converted automatically.

Personally, I prefer this method so I can use the same script on PC and Linux. Well, at least for relative directories.