i*ve got al litte prob wink

i have a var wich content is "13is7 idle for $ $+ duration(<idle>) singed $ $+ duration($ $+ calc($ $+ ctime - <signon>)) ago"

<idle> and <signon> are replaced later and the content looks like this "is idle for $duration(23312) singed $duration($calc($ctime - 1092754201)) ago"

now the identifiers should do there job but i don't know how i get them doing it because they are in the var :x