Sounds like it's an experiment worth conducting (and drinking!). Some of the acid from the vinegar will go into splitting the sucrose into "invert sugar," which is a combination of glucose and fructose, both of which are fully fermentable. However, the caramelizing from the cooking process will turn some of the sugar into non-fermentables but it's hard to predict how much exactly. I'd take a wild guess and treat it like dark brown sugar (which is sucrose with a little molasses) or dark Belgian candi in your calculations. Are sugar and vinegar the only ingredients? If there's butter in there, it may impact head retention.
Stop using so much caramel malt. Your beer will thank you.
(yes, Carapils is a caramel malt...so is Special B)
pujwI HIq Mild Ale
KPA Khitomer Pale Ale