Session variables in an extractor pattern

Is it possible to "place" a session variable in an extractor pattern? I have a a json object as in the example below for a map that appears. In addition to the page that I'm viewing it also lists other locations. I currently extract each item, then setup a loop to compare the id of each item too the id of the page that I opened.

www.somesite.com/viewpage.aspx?id=~#PAGE_ID#~

{"id":1,"lat":46.3629,"longt":7.3810},{"id":3,"lat":47.78954,"longt":6.753,...}

If this isn't possible it would be nice to have a feature in extractor patterns that would use a session variable:

"id":~#PAGE_ID#~,"lat":~@LAT@~,"longt":~@LON@~,

where ~#PAGE_ID#~ is for example 3 and results in finding "id":3,"lat":47.78954,"longt":6.753

There is not a way to put a

There is not a way to put a variable into a pattern. You would either need a RegEx in the token, or if the value is dynamic (like you describe), you would need to get all the matches, and use a script to find the one you were looking for.