javascript - JS Regex: Replace all but first -

this question exact duplicate of:

• use regex replace first occurrence of substring of blanks 1 answer

how can make regex replaces occurrences of word first?
have webpage loads of text , header @ top. want make regex replaces occurrences of word first because don't want header change.

var count = 0; text = text.replace(myregex, function(match) {     count++;     if(count==1) {         return match;     }     else {         return myreplacedvalue;     } });