The OTO SAT systems are made by a French company called "ZEN-RAD" and are intended for sale, and use, within France. That is why they are programmed for the two main French satellites, Fransat and TNT.
However, the manufacturer has a solution for those wishing to tune in to other satellites and this is done by means of an additional, plug-in, programmer that can pick up a further 8 satellites, including Astra 1, 2 and 3.
If your Bi-Sat control box has a socket on the rear marked 'Clavier' (it looks like a telephone socket) then you can plug in the additional controller and get the satellite you want Astra 28.2.
The unit you require is a "Zen-Rad Clavier 8Sat" code no. 10289 and costs around €120. You will need to contact Zen-Rad direct and see if they will supply you directly. Their web address is;
www.zen-rad.com.
Destinea, a chain of caravan/motorhome dealers, in France, seem to be the largest distributor of the OTO SAT systems, so you could also try them.
Best of luck!