Centering the links menu bar

Hoping someone might be able to help me here… I have a links menu bar running horizontally across my website just below the header. It was one created in the WordPress Stylesheet under #menu and #navcontainer ul type layout and hosted in the Header theme file. Thing is. the links run from left to right so if I only have a couple of links they are sitting on the left hand side when I would much prefer if they were centred. Does anyone know what code I would insert and were I would insert it in order to make this work?

Thanks for any help anyone can provide.