Communicate with an attached COM device

We have some forklift mounted LXE devices with attached label printers connected via a serial cable on COM2 on the LXE unit.  They are connecting to the UNIX server over telnet.  Calling "C$LOCALPRINT" allows us to send communication packets to the printers, but how would I go about getting a response from the printer?  We have terminals ranging in age from the VX1/VX2 DOS-based models to the newer Windows CE models.