OK, thanks for making your situation clear. I am afraid there is no really good reply, though.
* You seem to fly the P2002 as an LSA, that is a European classification but few planes are registered to it in BE;
* There is little offer, perhaps even none at all, of commercial rentals for this category of aeroplane round here;
* There are a fair number of P2002's around, however they are generally registered as ultralights, and you could only fly them legally on an ultralight license. This being a national matter, i.e. governed by Belgian authorities, you would have to offer first a valid medical, then pass theoretical exams, then fly with a registered BE ULM examinator. Your Russian PPL might help with the first two, I have little help to offer there but others might; the practical test should be quite feasible and not expensive either, but it might take its time.
* Your best bet could perhaps be to fly on a European PPL, issued on the base of your present PPL; join a flying club as a temporary/guest member, a club that has a suitable LSA available to members; get checked out by the club's instructor(s). But I have not the slightest idea of the conversion process;
* One club that I can think of is the Aeroclub Brasschaat at EBBT, I think they have a couple of tri-wheel low-wingers registered as LSA but I cannot really be sure.
* the authority governing Belgian licenses can be found at
https://mobilit.belgium.be/en , I have always found these people very polite and serviceable but they are quite understaffed these days so a bit of patience might be required
As an afterthought, as I re-read my own words: flying as PIC might be a lot of bother, and a bit of cost, too, perhaps more than it is worth. Why not consider flying with an instructor as PIC? I think most clubs would be glad to welcome you to this formula.
Good luck, and feel free to inquire further!