I haven't seen an example specific to this product.
However, there is a good overview of accessing dll's in LabVIEW available at http://zone.ni.com/devzone/conceptd.nsf/2d17d611efb58b22862567a9006ffe76/b26a875aca51c567862567ca0055ff24?OpenDocument
As for the specifics of your dll, you will need to consult the documentation that came with it.
steve, probably way too late and you probably already have the answer, for anyone else that comes along...us digital makes a breakout box called the sei-ada. with this, you can pick up the analog ouput and input through a labview compatible board.