I need the help of some RegEx gods here, as I've tried for two hours and can't wrap my head around this:

Sample source:

```
DisplayText="cf font=&quot;Arial" size="10" complexscriptsfont="Arial&quot; complexscriptssize="10" asiantextfont=&quot;Arial" fontcolor="595959"">

```

I want to replace all instances of " with `&quot;` but only if these are inside the enclosing ". I.e. the above should become:

```
DisplayText="cf font=&quot;Arial&quot; size=&quot;10&quot; complexscriptsfont=&quot;Arial&quot; complexscriptssize=&quot;10&quot; asiantextfont=&quot;Arial&quot; fontcolor=&quot;595959&quot;">

```

The exact structure of the text inside DisplayText is unknown and varies all the time, but whatever the case, we don't want " within the outer ". As you can see, the outer " are left untouched. This should only occur in strings starting with DisplayText=" and ending with ">.

So finding the strings that need editing is easy:

```
/DisplayText\="(.*?)"\>/

```

Now we just need to replace " with `&quot;` *within* $1 only.

This is for PHP.

Help would be much appreciated!