Sure, here ya go....
Usage: (setq str "MainRack|W14X43")
(setq newstr (strip2bar str))
(defun strip2bar (str / pos)
(setq pos (vl-string-search "|" str))
(if (not pos) (setq pos -1));set pos incase "|" not found
;increment pos by 2, 1 for 0 vs 1 based index, 1 for next character
(substr str (+ pos 2))
)