Running Totals - Extracting specific lines

Hello, I'm new to the forum, but I sure hope someone can help me! I have a report due by tomorrow at noon and I'm really stumped!

I have a group and a subgroup, and I want to do a running total on the subgroup, *BUT* I have to total the lines of the subgroup separately. Here is a sample of what my report looks like: My main group is the date, and the subgroup is the machine (folder, 3knife, cutter trimmer). For each date, the folder could be listed 100 times, so that's why its group as such.

11/06/2005
Folder 30,000
3Knife 5,000
Cutter 10,000
Trimmer 3,200

11/07/2005
Folder 42,000
3Knife 6,000
Cutter 18,000
Trimmer 5,000

11/08/2005
Folder 50,000
3Knife 5,000
Cutter 10,000
Trimmer 80,000

Now - how would I go about doing a running total ONLY for the Folder? I want to total up the 30,000, 42,000, and 50,000. Right now I am doing a running total and it will total up the Folder, 3Knife, Cutter, and Trimmer in for each date. But I want to extract only certain lines from each date (the main group.)

Am I making any sense with this? I've beat my head against the wall and come up with nothing. Please help!You have to do a conditional running total using a formula
{machinetype} = "Folder"|||That worked perfectly, THANK YOU!! :)