General:
* Concerning
* Regarding
* Respecting
* In relation to
* With respect to
* As for
* In terms of
* Relating to
* Pertaining to
Formal:
* With reference to
* In connection with
* In the matter of
Informal:
* About
* On the subject of
* When it comes to
The best word to use will depend on the specific context of your sentence.
For example:
* "Regarding your question, I'm not sure I understand."
* "In terms of the budget, we're over by 10%."
* "As for your request, I'm happy to help."
Please provide more context about how you are using "regards" so I can offer a more precise synonym.