See: https://www.msofficeforums.com/word-...numbering.html

The FilePrint macro in the attached document would require a minor modification, as you'll be progressing in increments of 3. Change:
For i = lStart To lEnd
to:
For i = lStart To lEnd Step 3

As the document uses DOCPROPERTY fields for the numbering output, you'll also need to change the field code, to use three fields coded as:
{={DOCPROPERTY Counter}+0 \# 0000};
{={DOCPROPERTY Counter}+1 \# 0000}; and
{={DOCPROPERTY Counter}+2 \# 0000},
respectively.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]