This is the code we use to pull the planned completion date for a task in the project called "Input Date". You could add another column with planned start date. Hope this helps!
displayname=Input Date
listdelimiter=<p>
listmethod=nested(tasks).lists
shortview=true
textmode=true
type=iterate
valueexpression=IFIN({name},"Input Date",{plannedCompletionDate},"")
valueformat=HTML