I never rely on the XLB file, but make my personal.xls rebuild my
customized commandbars every time Excel opens. More reliable, and it
doesn't crash itself on the 1st of every month.
I haven't bothered to publish my method, since I swiped it from so many
other places. Tom Ogilvy has posted a list of links on command bars on
this forum, several times, so you could find that by searching the
archives (http://www.google.com/advanced_group_search, use Tom's name,
this forum, and "CommandBars"). I used this information to help me
tweak John Walkenbach's MenuMakr.xls technique (http://j-walk.com),
expanding it to work on menus and commandbars, to indicate things like
custom button faces to use, and which standard stuff to remove.