Stumped by StringRegExp that matches delimited strings which contain a substring

Is there a StringRegExp pattern where you can match strings from within a delimited string (e.g. | delimited) that contain a substring being searched for.

#include <array.au3>
$text="|aaa|kcde|fff|akcde|aak|rpf|k|lir|"
local $allPipedContent = StringRegExp($text,"\|?(.*?)\|",3)
_ArrayDisplay($allPipedContent)

local $allPipedContentThatContainsK = StringRegExp($text,no idea :(,3)
_ArrayDisplay($allPipedContentThatContainsK)
#cs result needs to be
    kcde
    akcde
    aak
    k
#ce
    

Additionally as the substring is not always k ... it can be any string ...

is there an easy way to convert characters that StringRegExp interprets as control characters into literals that can be searched for (e.g. the "(" in the example below).

|aaa|kcde|fff|(akcde|aak|rpf|k|lir|