This description is for Finale 2002, but I believe that it was the same in Finale 2001 and 2000:1. Measure Tool.
Measure menu > Measure Numbers > Edit Regions...
The Measure Number dialog box appears.
If your Finale document was created from the Default Document, the top pane of the Measure Number dialog box will tell you that there is one measure region:
"Region 1, Measure 1-999 -- Display As 1-999"
2. Click the button "Add" to add a measure region.
This action will give you a measure region 2:
"Region 2, Measure 1-999 -- Display As 1-999"
3. When a measure region is highlighted, you can edit it using the fields below the pane.
Click Region 1, and set its range to this:
Region 1 Includes Measure 1 Through 1
Click Region 2, and set its range to this:
Region 2 Includes Measure 2 Through 999
Now the top pane reads
"Region 1, Measure 1-1 -- Display As 1-1"
"Region 2, Measure 2-999 -- Display As 1-998"
4. Click OK.
By The Way:
This is done automatically in Finale 2002, if you set a pickup measure by going to
Options menu > Document Settings > Set Pickups...
Peter