Sorting "insert citation" list in Word 2013

Jan 25 at 10:11 AM
Can anybody help me with sorting "insert citation" list? It is by default sorted by b:First instead of b:Last, so to have it properly displayed, I have to change all "firsts" into "lasts" in all files regarding citations (style, author etc.).
Where the hack can I find the file that determines the way of sorting under this button?