There is a way in Ver9 (only in V9, and you don't need the full catalog tools version!)
1) Close Design.
2) From the shortcut bar, click on the 3rd icon (or go to Start > 20-20 Technologies > Catalog Tools.)
3) At the bottom of the screen, click on the Spread Sheet Tab.
4) Top left, click on Catalog > Load Catalog.
a) Select your desired catalog from the down arrow.
b) Double-click on the Molding category.
c) Click on the Load Set button.
d) Pull the down arrow next to General and change it to Dispcat Variables
e) Click OK.
5) Now, look for the column called Unit of Pricing. This is the actual length per piece. Make sure the values are correct. (sometimes moldings can come in 9' (108") or 10' (120") lengths and the catalog may still be showing as 96".
6) Look for the column called Round Up Measure. When a design has moldings drawn, the programme will look at the length of each piece and round each piece up to this Round Up Measure value. You can use a smaller number to help control the amount of overage. So a Filler/riser molding with no overhang could have a Round Up value of 1". If a molding has a 3" overhang, I personally like to use a Round Up Measure value of 6". But you can use whatever value you want accordingly.
7) When you're done with these numbers, be sure to click on Catalog > Save Catalog to save your changes.