See http://word.mvps.org/FAQs/Formatting/CreateFraction.htm

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Suzanne S. Barnhill
Microsoft MVP (Word)
Words into Type
Fairhope, Alabama USA
Word MVP FAQ site: http://word.mvps.org
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> Is there a way to create new symbols for MS Word? I use the 1/2 and 1/4
> symbols often, but would like to use one for 5/8. Is there any way to create
> a 5/8 symbol?