The first method to enable ASP to run under apache is to use mod_perl and the ASP interpreter (Apache::ASP I think), this is probably the cheapest and most effecient way to do it.
Alternatively you can use a product like Chillisoft ASP to run ASP programs/scripts, but it's commercial and rather expensive.
Thirdly you could setup a rather strange asp2php (http://asp2php.naken.cc/) setup like I currently have running. In short I created a shell script which acts as a CGI - it uses the PATH_TRANSLATED environment variable and asp2php to convert and run ASP scripts.
Personally I would prefer the Apache::ASP method over the alternatives I mentioned, but if you want I can post my asp2php frontend (the only reason I implemented it that way was to maintain security in conjunction with cgiwrap).