Problem selecting the correct mkspec/qmake.conf file

In qtcreator I am trying to install a new toolchain using Options-QT4->+ . But when I browse to the qmake file it always selects the mkspec linux-g++ . This is not the mkspec I want. I want to use one that is for embedded arm. How do I tell it what mkspec folder to use?

Maybe I did not give enough info. I have downloaded a qt + gcc toolchain for the arm processor. I want to install it into qt creator, but I want to specify what mkspec it uses. How do I do that?