If you have many Find/Replace expressions to process, you could use arrays. See, for example:
https://www.msofficeforums.com/word/...fractions.html
Depending on your requirements, you might even keep your find/replace lists in a Excel workbook. See, for example:
https://www.msofficeforums.com/word-...html#post72330
This could even be extended to processing a whole folder's documents. See, for example:
https://www.msofficeforums.com/word-...er-footer.html
It also seems to me that, what you regard as "a code with 2000+ rules" might be greatly simplified through the use of wildcards and/or other, more efficient, find/replace expressions.