Can a submit button grab only a specified subform?

Hi All,

Just wondering if there's a way to change the default event code for an email submit button to grab only a specified subform (for example, page 1) in LiveCycle ES4? If so, could someone please provide the extra bit of code I need to insert?

Here is the existing code:

event name="event_click" activity="click"

submit format="pdf" textEncoding="UTF-16" target="mailto:.... " xdpContent="pdf datasets"/

Thanks!