set default value for [select], [checkboxes] and [radio]

Hello,
I usually set default value for dynamic text, taking this value using php (with snippet, plugin “allow php in posts and pages”), like this:

[dynamictext nome_campo ‘php function=23’]

Now I have to set default value for [select], [checkboxes] and [radio] fields.

How can I do that?

Thank you so much..

https://wordpress.org/plugins/contact-form-7/