How do I redirect 'register' on user blogs to buddypress register?

When I click on the default register link on user blogs, it goes to /wp-signup.php which is blank.

On my thesis theme I was able to redirect all blogs to the buddypress register in the custom_functions file.

I now use the bp-corporate.

How would I redirect all user blogs to the buddypress register page by default?

Thanks,

George