String array access with nonumeric argument

[Alincon2001]

StringVar array Isls:=["Oahu", "Maui", "Hawaii", "Kauai"];
isls[instr("OMHK",{s8_mast.CV_NUMBER}[1])]

This formula takes the first position of a field:
s8_mast.CV_NUMBER}[1])

Finds the matching position in a constant:
'instr' not 'in' or 'instring'

and finds the Island name in the array.

I thought perhaps this might help someone else.
r.m.