Difficulty setting the 'Open with app' to an alias

I am trying to set MacVim, installed via homebrew, to be the default HEX file editor. I started this task by creating an alias to MacVim.app located in /usr/local/Cellar/macvim/7.3-61 and placing the aliased app in /Applications. This allowed me to see and open MacVim from the Application folder (more info [here](https://apple.stackexchange.com/q/23653/4605)) . Now that the aliased app is there the "Open with app" selection via the RightClick->Info has the aliased app greyed out. To make matters worse it does not allow me to browse/select the real app located in /usr/local/Cellar. This doesn't seem to be asking to much here, any ideas on how to change this?