Yes. You can amend your current document.

1. I would recommend first creating a label mail merge set to reflect the column in an Excel spreadsheet that will contain your numbers.
2. Perform the merge to a document for editing.
3. That will let you see what it looks like. That includes the fields and the NEXT RECORD field.
4. Then switch to a COPY of your current document (a single page of labels) and insert the appropriate fields in those labels.
5. Set that as a main mail merge document attached to your data.