Firstly my problem is mathematical....

If a horse in a race finishes 7/17 (seventh of seventeen runners) and
another horse finishes 4/10, which has the greater merit? What is the
best way to represent such a problem?

If I import such fractions into Excel from a web page as text, how can I
best convert such data for mathematical manipulation, or back to a fraction?

This could be a problem where a horse finishes 17/17 as it would require
the first two digits (rather than one) to be selected.