Use Excel Macro to run a Word mailmerge

At the moment I have a folder with 3 files:

Setup Newsletter Labels.xls
Membership Database.xls
Newsletter Labels.doc

A macro in "Setup Newsletter Labels.xls" sorts and filters data from the "Membership Database.xls" and generates a "Label Data.xls" file with selected names and address details. I have this bit working.

At the moment I then manually open the "Newsletter Labels.doc" document in Word and run a mailmerge operation to import the data into the Word file, which contains the labels template, then I generate a "Newsletter Labels.doc" document for printing the labels to stick onto envelopes.

I'm wondering if I can automate this whole process via the existing Excel macro?

Also, if I move the files to a different location (or another PC) I have to re setup the "Newsletter Labels.doc" to re establish the link to the "Label Data.xls" file. I wonder if there's a way of using relative path names ( or some other approach ) so that it will always look in the current folder for the data file. I realise that this question might be better asked in a Word forum, but someone here may know the answer.