I'm using an ISAPI filter for rewriting URL's on IIS (IIRF). The filter process uses C regular expression syntax and a config file to list all the URL rewriting rules.

The config file is simple and works such that each line is a rule, like so:
RewriteRule  <regex match expr>  <regex replace expr>  [flags]

I have many rules working properly now and I need to extend this one explained below just a bit. It's simply a regex matching rule so I thought you all could help.
I have this rule working properly.

the rule below rewrites this url: /artists/999/my-band-name  into this url: /artists/artist.aspx?artistid=999&a=my-band-name
RewriteRule ^/artists/(\d+){1}/((?>([^?/\n]|/[^.?/\n])+)(?<!\.aspx))(/?)$    /artists/artist.aspx?artistid=$1&a=$2

Now I need to extend this so that it can take another "folder" at the end, which will denote the page to call. Like so:

/artists/999/my-band-name/shows  into:  /artists/shows.aspx?artistid=999&a=my-band-name
and
/artists/999/my-band-name/articles  into:  /artists/articles.aspx?artistid=999&a=my-band-name

I've tried this rule and many variations but it's not working.
RewriteRule ^/artists/(\d+){1}/((?>([^?/\n]|/[^.?/\n])+)(?<!\.aspx))/((shows|goods|fans|articles)+)(/?)$   /artists/$3.aspx?id=$1&a=$2

What would be great is to only capture certain page names in this format (shows|fans|articles) ... I've messed with this a LOT to get it working and I cannot. I think my negative lookbehind for the .aspx might be screwing it up? 

Any help or pointers is greatly appreciated! 

mason,

The problem with your new rule is that the first part of your expression, "^/artists/(\d+){1}/((?>([^?/\n]|/[^.?/\n])+)(?<!\.aspx))" will match all of the URL "/artists/999/my-band-name/shows", but your expression continues, requiring "/((shows|goods|fans|articles)+)(/?)$" to match as well, which it never will.  I don't see the point of the second alternative in '([^?/\n]|/[^.?/\n])'; can a band name really contain a slash?  Without this alternative, the expression matches fine, and I imagine the rule would look like this:

^/artists/(\d+)/((?>([^?/\n])+)(?<!\.aspx))/?(shows|goods|fans|articles)+/?$  /artists/$4.aspx?id=$1&a=$2

The '{1}' after '(\d+)' is unnecessary, so I removed it as well.  The changes I made here apply to the first rule as well.  I have zero experience with URL rewriting, so please forgive my ignorance if I have misunderstood something here.

 
Jeff