You need a payload xml in which is stored the path to the specific programm.
Here is a command group which you can edit to your needs (select the code then drag'n drop it on a free space in your VC command tree), save the attached launchprog.xml in the VC payload folder.
<?xml version="1.0" encoding="utf-16"?>
<!--VoxCommando 2.0.1.0-->
<commandGroup open="True" name="launch programms" enabled="True" prefix="" priority="0" requiredProcess="" description="">
<command id="276" name="launch programms" enabled="true" alwaysOn="False" confirm="False" requiredConfidence="0" loop="False" loopDelay="0" loopMax="0" description="">
<action>
<cmdType>Launch.RawParam</cmdType>
<params>
<param>{1}</param>
</params>
<cmdRepeat>1</cmdRepeat>
</action>
<phrase>start, open</phrase>
<payloadFromXML phraseOnly="False" use2partPhrase="False" phraseConnector="by" Phrase2wildcard="anyone" optional="False">payloads\launchprog.xml</payloadFromXML>
</command>
</commandGroup>