Regular Expression question

[Alchemist]

hello guys,

this is what I'm trying to accomplish:

I have a search engine friendly URL like this:

http://www.somesite.com/restaurants--reviews-compare-prices/Std_Country~Belgium/Restaurants_Cuisine~African/browsecat-1

by applying the following pattern:

^http://www.somesite.com/.*(/([a-zA-Z0-9_]+)~(.*))+/browsecat-([0-9]+)$

I'm trying to change the SEF url to this:

http://www.somesite.com/browsecat.asp?CatID=1&Std_Country=Belgium&Restaurants_Cuisine=African

by using code like this:

regex.replace(SEFURL,"browsecat.asp?CatID=$4&$2=$3")

however, all I'm getting is this:

http://www.somesite.com/browsecat.asp?CatID=1&Restaurants_Cuisine=African

which is only partially right. does anyone know how can I get this thing right? thank you very much in advance