I would like to:

1. remove any leading whitespace in the example matches below and
2. exclude matches that have at some position before the string a quotation mark AND at some position after the string another quotation mark (i.e. the strings that should NOT be matched are enclosed by quotation marks but the quotation marks will not necessarily be directly before and after the string).

I tried with combining negative lookbehind & lookahead but I somehow cannot figure it out.

Thank you so much!

My current Python Regex is as follows:

```
r'''(?<=[@])\s*[A-Z0-9.]+(?=\()'''

```

1. @STRING1( # Result: 'STRING1' --> works
2. @ STRI..NG2( # Result: ' STRI..NG2' --> okay, but excl. whitespace would be preferred
3. @ STRING.3( # Result: ' STRING.3' --> okay, but excl. whitespace would be preferred

**Example Text:**  

@STRING4("@STRING5( and maybe "another @STRING6("\_\_"maybe here is text") and @STRING7( " maybe & even another @ STRING8( " --- " and a "last" one " @STRING9( &"maybe some more "text"

Right now this returns (including leading whitespaces):

* 'STRING4'
* 'STRING5'
* 'STRING6'
* 'STRING7'
* ' STRING8'
* 'STRING9'

Desired return:

* 'STRING4'
* 'STRING6'
* 'STRING8'