You can't do that with SEROUT, but you CAN with SEROUT2... see the manual... quick example...

DataPin var PortB.0
Counter var Byte
DisplayString var Byte [18]

DisplayString(0)=$FE
DisplayString(1)=$01
For CounterA=2 to 16
DisplayString(CounterA)=CounterA+63
Next CounterA

SEROUT2 DataPin,T9600,[STR DisplayString\16]

This should clear the screen and display "ABCDEFGHIJKLMNOP" on the first line (assuming you have a 16 character display).