On the turbo-petrol engines the oil feed for the turbo is taken by a banjo fitting attached to the plug next to the figure 1 on your diagram above.
I would be worried about the balance of pressures in the lubrication system, though. Turbo bearings need a copious oil feed and tapping into the lubrication system without full knowledge risks running either the engine or the turbo short of oil pressure. Maybe a better idea would be to find a filter bracket from a scrapped turbo-petrol car, which will have the necessary connection and be constructed so as to divide the oil flow properly for both components? (Turbo diesels have a completely different oil filter).
Another question is whether the oil pump is up to delivering the required pressure and volume of flow? Any way to find out if they are the same on turbo and non-turbo cars?