42 Pa.C.S. § 2502: Certain persons not to appear as counsel.

(a) General rule.--Except as otherwise prescribed by general rule, an attorney at law who is an employee of a court shall not appear as counsel in such court. An attorney at law shall not appear in any court or in any matter in violation of any general rule relating to the practice of law or the conduct of courts, magisterial district judges and officers serving process or enforcing orders of courts.

(b) Law clerks.--Except as otherwise prescribed by general rules, a law clerk serving on the personal staff of a judge of a court of common pleas may appear in such court as an attorney at law before other judges of such court notwithstanding the provisions of subsection (a).