I ran into an interesting situation where back references overwrite previous changes in a regular expression. I needed a regular expression that updated a pattern but also checked for something that comes before the pattern.  It should leave everything before the pattern as it was before the updates.  There can be multiple matches of ...

In the following string: <div class="x" bla bla bla <div class="x" bla bla bla <div class="x" bla bla bla EXAMPLE STRING  I want to match: <div class="x" bla bla bla EXAMPLE STRING NOT <div class="x" bla bla bla <div class="x" bla bla bla <div ...