Thank you for clearing that up, then you enter 0.26 W, into your Longitude settings..
2 decimal places is fine, even 1 decimal place is acceptable, all that happens is that your receiver works out the locations, of all the satellites, from your Latitude, and Longitude, map reference, once the dish is set up correctly.
So you set up your dish, motor, and LNB, all at 0. enter your Latitude, and Longitude, into your receiver, and tell it to send the motor to 0.8W.
You then physically align the dish, to Thor 0.8W, get the strongest signal possible, tighten everything up and 0, on your motor, should then be pointing at 0.26W.
Once done you can send it to your furthest East, then West, satellites, note the signal quality readings, and send it back to 0.8W for fine tuning, slightly adjusting the elevation options, to get the maximum signal possible, on all available satellites.