Since \&( does not match the regex I posted, the value of $* ends in ~kw/org here rather than ~owoorg, so the substitution on $=[0] fails because \w doesn't match a /. Even if it succeeded, the subsequent eval would attempt to define the subroutine Hkw/org (giving a Search pattern not terminated error) instead of defining the subroutine Howoorg as the OP intended.