To convert a text value to a number using a defined rule in Excel, say a
macro or some other formula? Take for example, say the value "Instructor"
mapping to 09141920182103201518 with each letter corresponding to its
position in the alphabet represented by a two digit number. However, the
longer the word, the longer the numerical string, so I would like to be able
to limit this in some way.

I do not yet know which words or phrases will be entered, but is there some
hash function available that will keep the numeric strings relatively short?