restrict levels for code in posts

I have some custom coding in my posts/pages that if edited in visual editor, it would auto-format it and break the code.

My question is, is there a way to keep my custom code in the post/page content (without having to hard code it in the template), while simultaneously allowing other (non-admin) users to use the visual editor for content only.

This way, non-admin users can edit a post/page, but only a certain portion of it. The code that the visual editor would break, remains untouched.

A plugin that I missed?

Thanks,
Tom