Here is an attempt to produce requested expression : 
```  
  ^([a-zA-Z0-9]+)\.[(.+)]$
```
Note that this may be inaccurate or outright wrong. But you probably know that I'm a language model, not a calculator, since you're asking complex STEM related questions
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence