How do I access / map manually added ligatures in Word?

Hi guys,

I've created a client font that has some manually added ligatures. It works fine on Apple, because OpenType does the work for me. But can I get these ligatures to work in Microsoft Word? They're not mapped to any key on the keyboard, so how can I access them? I'm making a small manual for the client how to use the font. If this means I have to map these extra ligatures to some keys, this is fine with me.

Can anyone help me out here?