I just had a rather interesting idea for you.
Simply treat the baby as if it were any other human being that your co-worker brought to work.
"Hello, John/Suzie/Star-Lord, pleased to make your acquaintance."
You can shake their tiny hand, if that feels natural to you.
If said with a smile, then it's unlikely to offend anyone, and even if everyone is into the "goo goo gah gah" talk, maybe they'll find your alternative approach amusing. At the very least, you will appear capable of interacting with the children of your coworkers, and you won't look as stand-offish. Worst case scenario is that you'll be known as the weirdo that talks to babies like they're grown ups, but I don't think I've met anyone who thinks that way.
