If you need to display a wizard screen ONLY if a certain Task Sequence is selected, this is a method to accomplish this.
1. Add a custom step in the Task Sequence.
2. Using the Wizard Studio, build your custom page and use the following condition to force it to display only when your custom step is detected.
FindTaskSequenceStep(“//step[@name=’Test’]”, “” )
Note: The FindTaskSequenceStep function is case sensitive.