Looks like nobody is answering. I have an idea that might work, but I haven't implemented it.
You can copy equations and paste them as MathML into a text editor (you may need to set the option in Word to "Copy MathML to the clipboard as plain text"). So, you should be able to copy and paste them using VBA into a file. You should be able to import that mml file into Mathematica.
I tried to open an mml file in Mathematica and couldn't get it to work, though the format is supported. Anyway, you might want to try something like that.
