You could use a "Begin a Conditional (If Statement) Block" action combined with the "{ACTIVEWINDOWTITLE}" token, to check whether the active window title starts with "Vectorworks Studio", and it not, either perform a different function (by using a "Condition Else" action), or do nothing at all (by enabling the "When this block is reached, exit command if condition is met" option).
E.G.
Begin Text Compare : [{ACTIVEWINDOWTITLE}] Starts With 'Vectorworks Studio'
End Condition - Exit when condition met
Scroll mouse wheel forward 1 click
Say, 'UP' (and wait until it completes)
If you use the option to exit the command, you'd want to apply the same actions to the other command you want to use when another applications is active, by inverting the logic so that it exits when the application is anything but "Vectorworks Studio".
Both commands would still execute, but only one would perform any actions aside from the window title check.
These topics may also be of use in addition to the official documentation:
Control flow (If, Else, ElseIf, Loop, Jump) basicsVariables and tokens summed upAnother option would be to have separate profiles for the applications you're using.
You can enable the "Enable Auto Profile Switching" option on the "General" tab of the VoiceAttack options window, so you can then use the "Enable profile switching for the following windows or processes" option at the profile level to list any windows you want that profile to apply to.
For commands that apply to multiple profiles, you can use the "Include commands from other profiles" option at the profile level, or the "Global Profiles" option on the "General" tab of the VoiceAttack options window, to include command from one or more profiles into the active profile.