Regex question

setting up a simple template library I am running into the following problem $newline = pgreg_replace("%%(\w+)%%", "$HTTP_POST_VARS[\\1]", $line); generates the following error. Parse error: parse error, expecting T_STRING' or T_VARIABLE' or `T_NUM_STRING' in /export/home/virtual01/bsc/test.php on line 10 getting rid of the $HTTP_POST_VARS and just replacing with \\1 works correctly and vice versa if I remove the \\1 and replace with something like $HTTP_POST_VARS[username] it works fine. the goal is to prefill in form values... pretty straight forward. the same thing works in perl ..well the equivalent expression anyway $line =~ s/%%(\w+)%%/$MY_DATA{$1}/g; Just wondered if anyone new a quick work around. thanx, Daniel Murphy ps. latest snapshot w/ apache 1.3.12 on Solaris 8