proper way to set register values during init?

(set-register "z" "[complex html I want to be able to insert into org-mime-htmlize'd emails]") does seems to fail in a couple of ways. I've seen `registerv-make` too, and that doesn't seem to do the trick. Can anyone give me a simple template to have registers set to single- or multi-line-strings during init? (for bonus points, how about a kmacro? I have a certain sequence for interacting with gnus to process hundreds of emails a day that I'd love to not have to redefine every session)

(set-register ?z "[complex html I want to be able to insert into org-mime-htmlize'd emails]")

Thanks!

I.e. interactive registers are identified by *characters* rather than strings. See also `C-h i g (elisp)Basic Char Syntax`

> how about a kmacro First name the last macro defined with `M-x kmacro-name-last-macro` then go to your config file and run `M-x insert-kbd-maco <ret> name <ret>`. Now you should be able to invoke the macro with `M-x` and whatever you named it.

thanks!