You could book the first couple days as standard view, modify your current reservation to drop those days, then wait list the rest of the standard view days. If the wait list filled,
DVC would automatically drop your lake view portion and fill it with the standard view (as long as you set up the wait list this way.). You might end up with a split room stay, but remaining in the same hotel this really doesn't seem like a big deal, as long as you plan on being at the parks that day. You have to pack the bags, but Disney will move them for you while you are away.
Or, you could wait list the entire trip for standard. This would avoid a possible split stay, but is less likely to fill. Longer wait lists are always less likely to fill because all the wait days have to be available at the same time.
A shorter wait list from a different member that was overlapping your dates would fill first, if only part of your dates became available.
One risky way to do what you're attempting, would be to book both the front and back end standard view dates, and just wait list that single day. Keeping the one day lake view that you have booked currently. The risk is that if it didn't fill, you might have to move twice. Again, not the end of the world since it is in the same hotel. But personally I would rather spend the extra points, than have to be "in the suitcases twice" during a one week stay.