[NTG-context] Processing URL with TeX macros

Hello ConTeXist. I would like get right URL, when I use \useURL command. Is there possibilities put any TeX macro to first and second parameter? It was clear to me why this is about, but I need it for one application (in the cycle I change URL addresses). Thanx Jaroslav Hajtmar Here is my minimal example: \setupinteraction[state=start] \def\myurl{http://mydomain.com/path/} \def\myfile{mypdffile.pdf} \def\urltext{This is link to my file} \useURL[okexample][http://mydomain.com/path][mypdffile.pdf][\urltext] \useURL[problemexample][\myurl][\myfile][\urltext] \starttext \from[okexample] -- OK \from[problemexample] -- link problem \stoptext