LISP: A dynamic car

I have a complex list of lists and want something to check the second element of every list of the list in the loop, any supported features like this?

>>16
>>15
thanks but I don't know lisp well enough to use that

this is the code I came up with


(defun type-lint(pass &optional buzzword)
    (let ( (temp ()))
      (con temp (car arch))
      (setq arch (delete (car arch) arch))
      (loop
       (if (null arch) (return))
       (setq temp ())
       (if = (car :(car arch)) `must-be-supported-by
           (setq arch (delete (car arch) arch))
           (con must-be ((car (car arch)) (car temp)))
           (setq arch(delete (car arch)))
           )
       (if = (car :(car arch)) `a-kind-of
           (setq arch (delete (car arch) arch))
           (con a-kind ((car (car arch)) (car temp)))
           (setq arch(delete (car arch)))
           )
      (if = (car :(car arch)) `must-not-touch
           (setq arch (delete (car arch) arch))
           (con must-not ((car (car arch)) (car temp)))
           (setq arch(delete (car arch)))
           )
      
        )
    )
)

it's not general or elegant. relies heavily on knowing the data before hand. and has some lambda's needed errors, but this is about my current knowledge level