Who says you can't vl-bb-set functions?

[john.uhden]

Well, only the AutoCAD help.

But here's a workaround example...

(setq x '(defun c:hello nil (alert "   HELLO\n   WORLD!")(princ)))
(vl-bb-set 'code x)
(eval (list (eval (vl-bb-ref 'code))))

Though @Sea-Haven is convincing me to use a script, I am still trying to be persistent in using vla-sendcommand on an xref.

I imagine that x really has no length limit, and you don't have to escape any quotes, so...

[hak_vz · Accepted solution]

Or use vl-propagate:

(setq xx '(defun c:hello nil (alert "   HELLO\n   WORLD!")(princ)))
(vl-propagate 'xx)
(eval (list (eval xx)))

[john.uhden]

Very cool!