Calling Classes or Functions

[banfw001]

Hello All,

 

I am trying to turn a PHP application I made about a year ago into a WordPress plugin. I'm reasonably new in the world of WordPress plugins and have what I think will be a simple question. 

 

My plugin creates a shortcode, and when the WordPress page with that short code on is loaded, the program calls a function and displays it. My question is, within that function, how do I create a link or button (or something else) which will run the chosen function. Here is what I mean:

function welcome() {
?>Welcome. This is the first screen of the plugin. Click <a href="???">here</a> to register.
}

function register() {
register here
}

How would I make the above piece of code work. My thanks in advance.