Marissa82, I'm going to guess that the pasta sauce that you are talking about is probably
made with tomatoes and calls for red wine. You would do better to just leave it (and any substitutions) out rather than mucking it up with grape/cider juice.
Wine is primarily used for 4 reasons:
1) Flavor - the actual flavors of the wine which are developed during fermentation and storage
3) Tenderizing agent for meats
4) As a Solvent - in a sauce with tomatoes for example, the alcohol liberates some flavor components that can then combine with other flavor components to create new flavors. It's like why you sear cubes of meat when making a beef stew - the Maillard "browning reactions" of the proteins and natural sugars in the meat produce new flavors that add a depth of flavor that you would not get otherwise.
I have seen some really bad ideas for substituting things for wine ... but perhaps the most logical (flavor wise) I have found is here
. If anyone has a problem linking to this site (like I have today) let me know and I will cut-n-paste from my cached page of this site.