Garry,
I am assuming you are referring to field PRA-5 (00689) Specialty – 2.3.1 HL/7.
This is a CM type field so you can simply place the specialties in each component as you described. There is no need to change the field.
However, the standard length is 100 bytes so you might want to change that to assure you have sufficient room.
Jim Kosloskey
email: jim.kosloskey@jim-kosloskey.com 29+ years Cloverleaf, 59 years IT - old fart.