DubMan can run external commands as a step in the video processing sequence. This is designed to allow you to run programs such as audio manipulation software to perform tasks not supported by VirtualDub. To use this function, the program you're running must be completely controlled from the command line and terminate when its done performing its task. For example, BeSweet (http://dspguru.doom9.net/) is an excellent command line audio manipulation/encoding tool.
To use this feature, check the Run external program box and type the full command line used to run the external program into the text field on the Run Program tab in the Add/Edit Job dialog. When writing the command, you can use %1 in the place of the input file and %2 in the place of the output file. These will be replaced with the value from the Input File Name and Save File Name fields respectively from the Standard tab. This allows the external command to work with bulk files and have its input/output files verified by the file checker.
To help figure out if you're running the external program correctly you can enable the run command console window. This feature can be enabled by checking the "Show run command console" box in the DubMan settings dialog. This will show the output of your run command(s) as the processing occurs. However if your program writes out a lot of output (like BeSweet), using the run command console can severely decrease processing performance which is why it's disabled by default.
The output from every run command process is stored in the runcmdlog.txt file in your DubMan directory, regardless of whether the command console is enabled or not. A link to this log file is included in the DubMan folder on the Start Menu.