The phrase "in/with regard to" is a common way to introduce a topic or subject that is being addressed. However, there are several synonyms for this phrase that can be used to add variety and depth to one's writing. For instance, "concerning" is an excellent alternative that is commonly used in formal contexts. Another option is "regarding," which is similar in meaning to "in/with regard to" but more concise. Additionally, "pertaining to" is another synonym that can be used when discussing a particular subject. Other options include "related to," "connected to," "associated with," and "in connection with." Each of these words can be used interchangeably with "in/with regard to" and can make writing more interesting and diverse.