How to I replace or substitute multiple unique numeric records in 2 columns
with the related textual value from another column.

For Example:
I would like to replace or substitue Column C & D records with the related
textual value of Column A.

Column A "name" = Textual value
Column B "regnum" = unique id

Column C "sire_num"= unique id relating to Column A "name" - textual value
Column D "dam_num"= unique id relating to Column A "name" - textual value

Looking forward to your help.