I called IN and the representtive said Indiana isn't able to read pdf attachments.  They said if your tax software--ProSeries--doesn't allow you to submit a dummy IN K-1 to show the pass-through withholding, then you MUST HAND FILE RETURN.  

You were 100% correct.  ProSeries, please add this option so all your IN filers with passthrough withholding don't have to burden their clients with Hand Filing.