what can I use instead of wine? A bit of veg broth, chick broth and a bit of beef broth?

Port wine adds sweetness and dried fruit flavors so I would add some chopped dried cherries, prunes or raisins (2-3 tablespoons?) and maybe some orange zest (1/4 teaspoon or so?).
Or I'd sub 1/8 cup of the broth with balsamic vinegar for adding some sweetness and tang.
None of these suggestions would be equal to the port wine but I do think they would help a lot.

The port wine is an important component as far as flavor profile, so you will be losing that. But of the stocks, I'd suggest a good beef stock or a mushroom broth-- not the powdered type but the liquid you get after rehydrating your wild, dried mushrooms.

I think chicken broth or beef broth would work fine.