How to add "Content-Type: application/nss" from ATT IPTF invite to siprec XML

I am looking for a way to add "Content-Type: application/nss" to the SIPREC xml.

see below example invite we are getting from ATT. this feature "infopack" is an optional item that is available based on setup within ATT mgt portal, this data is included on the initial invite

--as-boundary
Content-Type: application/nss
Content-Transfer-Encoding: 7bit
Content-Disposition: session; handling=required

VER,1.00
PRN,t1113,*,att,1993
IAM,
JUR,412945
CGN,04,u,1,y,4,4121231234
USI,rate,c,3,c,1