I have got it to work using DIV32 command.
Thanks to all!!
Here is the updated code:
mainloop:
WTotal=(W0+W1+W2+W3+W4+W5+W6+W7)
dummy = WTotal*10000
WTotal2 = Div32 1275

LCDOut $fe, 1 ' Clear LCD screen
LCDOut "AUX IN Volume:"
'Charac 1234567890123456
LCDOut $fe, $c0 'Jump to second line
IF WTotal = 0 Then LCDOut "MAXIMUM (100%)"
IF WTotal >0 AND WTotal <130 Then LCDOut "-",DEC(WTotal/10), ".", DEC1(WTotal), "dB (", DEC(WTotal2/100), ".", DEC2(WTotal2),"%)"
IF WTotal >=130 Then LCDOut "-",DEC(WTotal/10), ".", DEC1(WTotal), "dB (", DEC(WTotal2/100), "%)"
Pause 100