1000 needle altimeter script help

HI

I have been strugling for the whole weekend to wright a script for a analog altimeter that works with a 1000 ft indicator needle...any help whould be appriciated.

Here is my sioc script

var 0012, link USB_stepper, name stepm, device 0, output 1, posl 6, posc 0, posr 4, type H
Var 0013, name ALT
{
&stepm = &ALT + 1800
}
Var 0011, name Alti, Link FSUIPC_IN Offset $3324, length 4 // var
{
L0 = V0011
L0 = ROUND L0
IF L0 > 1
{
L0 = L0 + 3600
}
L1 = L0
IF L1 < 3600
{
L1 = L1 - 3600
}
&ALT = L1
}

If you can help with the millibar script, then it whould be a bonus then im done with this instrument..

Regards

Marnus Hugo
(Suid-Afrika)