InfoPath Dev

I have created an Infopath form that submits data via an Email connection. I am looking to populate the Subject line of the email with the following "PPI Investigation for Incident # (number from an associated field in the form)". Unfortunately with my limited knowledge of Infopath I am unable to figure this out. Any help would be greatly appreciated.

 Thanks in advance.

while creating the email submit connection, navigate to the screen , where we give in to ,cc ,...subject.

aginest Subject text box click (Fx) -> insert function-> text -> concat

instead of "double click to insert field"  "PPI Investigaton for Incident" (includes the quotes also),

on the second "double click to insert field" -> double click and select your field (whose value you want to appear in the subject line)

delete the third "double click to insert field" along with the comma,

so your formula will look like

concat("PPI Investigaton for Incident", yourfield)