Of course there is a way to do this. Make sure that every selection in your languages list box (always a single one I guess) sets a variable vLanguage. Variables will not be cleared if you reload your document so they can be used to pass parameters from the UI to your script. This is a way to load only one language in an otherwise multi-language document (for example by repetitively passing a parameter in the task definition and repeating the reload for every language available)
But it's still not clear what you are trying to accomplish. As far as I know, QV documents work best if they include every piece of information and data that an(y) end-user could possibly be interested in. Not by asking the user what he's up to and then reloading just that bit.
As an example of how this works in an extremely dyynamic way, you could store the preferred language of every user in the SA table, and let QV throw out all irrelevant languages by simple data reduction when the user opens the document.