Yes you can use old opened bottles of wine for cooking with.
The old wine that has been opened is perfectly safe to cook food with as long as the old wine is still good and hasn't gone bad.
I use some old opened wine to cook with and it works out great even though it would not taste good in a glass the wine goes good with cooking.
So as long as the opened bottles of wine you have are good you can safely use the old wine for cooking with as long as the opened bottles of wine has remained refrigerated.
No need to throw out the old opened wine if it's still good enough to cook with.