tidy variables in strings

I'm rewriting PHP code written by an other developer and first thing I do is tidy up the code, which works great with code > reformat code.
I've altered the settings for PHP how I like my code to be, I can't find one thing though, reformatting strings with variables.

The code I get has strings like these:

 $string = 'A bit of text ' . $aVariable . ' and then some more text.';

 $string = "A bit of text " . $aVariable . " and then some more text.";

 $string = "A bit of text ".$aVariable." and then some more text.";

 $string = "<htmltag parameter1=' " . $var1 . " ' parameter2=' " . $var2 . " ' para='value' />";

I want them to look like one of the following two

 $string = 'A bit of text '. $aVariable .' and then some more text.';

 $string = "A bit of text $aVariable and then some more text.";

I thought I could find it on the spaces tab in settings > editor > code style > PHP, but I was wrong or I'm missing it.
Can somebody tell me if this is possible?