Thinking about it .... you can just use SERIN and SEROUT in regular 8N1 format:

Receiving - 8N2 instead of 8N1 is of no consequence since the stop bit is the same as the idle position (the extra stop bit will be ignored with no effort on your part)
.
Transmitting - you can use “DEFINE CHAR_PACING VALUE” to pause between transmissions of each byte. (Just pause the length of on bit transmission to get the second stop bit)

What baud rate do you want? (e.g., VALUE above would be 104 or more for 9600 baud.) See the PBP manual.