Bernie Pillsworth was a wizard who worked at the Ministry of Magic. Ron Weasley, disguised as Reginald Cattermole, had to fetch Bernie to help him stop the rain from falling inside Yaxley’s office. (DH13)
It is implied that he is skilled enough to help Ron Weasley, disguised as Reginald Cattermole, stop the rain falling in Yaxley's office, as Ron is told to fetch him. (DH13)
In the text, Ron falters to remember if "Pillsworth" is Bernie's last name, so it is not certain that it is his surname.