Assuming that (1,200,5,I) is the correct value, then the baudrate may be incorrect. Try e.g. COMRAW 9600 and use DECODE 9600.RAW to display the result. Do not forget to actually use your stylus while running COMRAW. I expect to see something like:
sBtn=00,xPos=03799,yPos=02328,zPos=00026,Stylus:MoveOnly
sBtn=01,xPos=01789,yPos=03436,zPos=01418,Stylus:But1Down
sBtn=00,xPos=01794,yPos=03433,zPos=00016,Stylus:MoveOnly
to be reported. May be COMRAW 38400 will do?