How to remove all non-alphanumerics?

I have a custom jscript function that is currently defined in
<msxsl:script> tags and called from xsl. I'm hoping to increase
performance by rewriting it in xsl.

The part I'm stuck on is how to match (and remove) all non-alphanumerics
except underscores and hyphens. A regular expression does the job in my
jscript function:

sOutput = sInput.replace(/[^\w-]/gi,'');

My first thought was to use translate(), but the second argument would
have to contain every possible character I want to remove, which seems
pretty unwieldy. 

Is there way to specify a range of characters to match using
translate()? Or better yet, is there a way to replace characters by
specifying the just the ones I want to keep?

Thanks,
Kevin Collins

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