List attribute values from shortcodes in a post

Hello,

I want to collect some data from all the shortcode in a post.

There would be multiple shortcodes in the same post. Like:
[mytips id=”101″ zcode=”abcd”]
[mytips id=”321″ zcode=”efghijk”]
[mytips id=”423″ zcode=”mnop”]

I need to get all the values of attribute zcode. So I can get a list like:
abcd, efghijk, mnop

Thanks in advance