One can also use MS Excel?
1. Open a blank Excel Sheet. Go to Data tab > From Text/ CSV.
2. Select the CSV > Click Import
3. In the new dialog box, click Transform Data. You may choose "Tab" for Delimiter, if required.
4. In "Transform Data" dialog box, right-click the field (you want the leading zeros), > Change Type > Text.
Click "Replace Current" for Change Column Type.
5. Click Close and Load.
6. Save the Excel file.
7. In ArcGIS Pro, execute Excel to Table.
*Oops. I should have read your post completely. 😅
Think Location