Change the automatic generated "Profile" Link

Hello,

i included the login in my sidebar. Everything works fine.
But when i click on the link “Profile” it shows me my typicall WordPress Profile page.
I dont want this.
So i have another frontend profile page. Every User is under following Url: http://www.mysite/questions/user/*the_user_name*

My question is, how and where can i change the standard link to the profile so it will link to my other site?

Hope you can help me.

http://ww.wp.xz.cn/plugins/login-with-ajax/