Make A Choice In An Extensible List

I have to introduce often the same entry (i.e. a firm or commerce name).
To avoid having to make all te time the same entries and to avoid entring the same firm with different spellings I imagine making a choice from a list, list that would be able to "learn" new entries.

Example: When I type the "D" of "Dupont de Nemours", Excel would propose all entries beginning with a "D", and if I introduce a name that doesn't still exist in the list, I should be made attentive to that fact and proposed to add that name to the list.