ideal would be a probe/poll function which to be configured with a script for sending a serial Hex command an parsing the received message to human readable data.
source would be a TCP/IP:port  address which is in our case a TCP/iP to serial converter at the remote side, converting the data to the serial devices.

I found "Mango" a very useful program to do this, but its missing the android client and may be more written for SCADA projects.
( in fact its an amazing program in its flexibility. )