Omitting certain content from Post excerpts

I have an issue where I need to filter certain content out of excerpts, so that when I am viewing a category listing, the content is “formatted”, and when the reader clicks the heading to read the article, the entire content is displayed.

For example, if I were to wrap some content in a shortcode, like this:

[noabs]This is content that should not be in the category listing[/noabs]

It would not show up in the excerpt, but would be in the article.

Any help is appreciated.