Word 2007 custom dictionary including Māori macrons   

I have custom dictionaries in the Māori language. I wish to use these in Word 
2007. Whenever I save them in Unicode format it changes the macron - the line 
above the 'a' - into a square box following the 'a'.

When I right click on a spelling error, the word shows correctly in the 
right click menu e.g. ātō; but when I select that, the word in the document 
is changed to 'a' square 't' 'o' square. 

We use NZ English and have the Māori keyboard installed to enable the typing 
of macrons.

I have saved the .dic file in a number of unicode formates with various 
conversions applied and I can't make any of them work. 

I got the dictionaries from this site, the top download on the page.
http://www.maorispellchecker.net.nz/download.htm
I have tried both sets of files that come with it. 

I've been trying to make this work for two days now and am my wits end. :(

date: Sun, 6 Jul 2008 20:44:01 -0700   author:   Hannah