You can't do that right out of the box, but hopefully Alfred is powerful enough to allow you that. I made this little workflow that does what you want. It could be better but it's work well.
Download it here: http://cl.ly/NdGL and add a new Fallback Search in the "Default Results" section selecting this workflow.
Does Alfred support an URL Scheme so that I can open it from other apps with an specific text? If that's not possible, is there an apple script or anything that would allow that? Thanks.
EDIT:
Just realized I can apple script that:
tell application "Alfred 2"
search "query"
end tell