A family of Microsoft word processing software products for creating web, email, and print documents.
I have been fascinated by fields for years.
I know of no way to make more fields but it is possible to format one the way you want with the switches you want and save it as an AutoText entry or even a Quick Part Building Block.
Here is the documentation on the ListNum Field.
.https://support.office.com/en-us/article/field-codes-listnum-field-557541b1-abb2-4959-a9f2-401639c8ff82?ui=en-US&rs=en-US&ad=US
Such an AutoText or Building Block can be brought into a document with a keyboard shortcut or a a key phrase in the name that lets you insert it with the enter key.
I have the QuickParts menu on my QAT.
If you want to do any of these, let me know and I will help you with it.