OK, it is working!
Thanks to all who helped and provided some food for thought.....
Code below for any others who need to do this:
Code:
                      OutA=$FFFF                                        'Initial value for word var - everything is OFF                      
                      PortDevice=$A                                     'Var from comm link
                      OutA.0[PortDevice]=0                              'This works!
'                      OutA.2=0                                          'Manual bit mod - works though  
'                      OutA.12=0                                         'Manual bit mod - works though
                      OutA_hi=OutA.highbyte                             'Splits into hibyte
                      OutA_lo=OutA.lowbyte                              'And into low byte of the word var
                        OutA_MCPReg = OLATA                             'Sets up PORTA output
                        OutA_DataOut=OutA_lo                            'Sets up data to be pushed to the MCP23S17 as the low byte
                        gosub SEND_OutA_2317                            'Send it
                        pause 10                                        'Wait a bit
                        OutA_MCPReg = OLATB                             'Sets up PORTB output
                        OutA_DataOut=OutA_hi                            'Sets up data to be pushed to the MCP23S17 as the hi byte
                        gosub SEND_OutA_2317                            'Send it
Happy New Year!
-Steve