The phrase "a certain dash" is correct and usable in written English.
It can be used to describe a specific quality or characteristic that is somewhat vague or not precisely defined, often in a positive or stylish context.
Example: "She walked into the room with a certain dash that caught everyone's attention."
Alternatives: "a particular flair" or "an unmistakable style".
A certain dashing, yet self-effacing columnist and talk show host for Federal News Radio.
He was a headmaster with a certain mechanical dash to him: a motorcycle-and-sidecar man, then the owner of a Lanchester, then, in retirement, the driver of a rather pompously sportif Triumph Roadster, with a three-person bench seat in front and two bucket seats when the top was down.
But if Edwards's killer lacks stature, there is a certain theatrical dash to his methods of undermining the 650 B.C. religious festival and athletic games being held in the city of Priene in Asia Minor by the 12 city-states of the Ionic League.
In The Birthday Party I employed a certain amount of dashes in the text, between phrases.
Callaghan never forgot that he had missed out on a university education and was not without a certain chippiness or a dash of menace: he was particularly sensitive to slights from better-educated rivals.
It's got a dash of the rough-and-tumble to it, a certain grit, a flair for dystopian aesthetic.
All of your hopes, dreams and wants get bundled up in this child being of a certain gender, only to get dashed when it turns out to be the opposite.
He deemed the album a "comic relief" and noted its contents of "fortified vocal harmonies, an occasional dash of keyboards, a certain production gimmickry".
A critic at Harper's magazine called it "a first novel… that comes with abundant expectations for its author [and] a certain eagerness to see those expectations dashed".
This will be confirmed by a certain series of blinks on a dash-mounted LED.
