I see some problems with points and commas and floating point and long and int.
Your calculation seems good.
Could you try a floating point calculation ? That is easier.
int sensorValue;
float milliAmps;
sensorValue = analogRead(analogInPin);
Serial.print("raw sensorValue = ");
Serial.println(sensorValue);
// Convert to milli amps
// The offset of 512 has to be determined, perhaps during startup.
milliAmps = ((float) (sensorValue - 512) * 5.0 / 1023.0 ) * 1000.0 / 66.0;
Serial.print("milliAmps = ");
Serial.println(milliAmps);