Short answer, yes.
When you create your step type, for the Specify Module you would use a SequcenceCall Adapter instead of your labview adapter.
You would have to have your sequencefile with your sequences already created seperately and you would set the sequencefile not to use a process model in the sequencefile properties.
Only problem is: I don't see any "Sequence Call Adapter". I am looking on the General tab of the Custom Step Type Properties, under "Designate an Adapter". Sequence Call is not an option. (I am using TS3.5)
When I select "None", which was my other guess, then the "Specify Module" button disappears.
How exactly do I set it up?
The reason you do not see the sequence call adapter is because it is hidden by default.
Go to Configure->Adapters and uncheck the 'Hidden' check box for the sequence call adapter.