Genealogy / Huthsteiner/Hutstein in Warsaw ~1763 [NEW]

Hello colleagues

I'm searching for the birth records of the children of Christian Huthsteiner. He was the court cashier at the Saxonian court in Dresden and moved with Saxonian duke to Warsaw and he obviously converted to Catholicism there. At least one of his sons, Heinrich Christian Huthsteiner, definitely was born in Warsaw between 1761 to 1763, but I do have any idea in what church he got baptised. Likely, several other children were born there between 1748 and 1763, too.

Christian Huthsteiner was mentioned two times as godfather in baptism records of parish Holy Cross, Warsaw downtown.

So, my questions:
where did Saxonian court members in Warsaw usually live (close to the palace ?) and what parish was incorporated there ?
Where can I find it's church records ?
Or did anybody find Huthsteiner/Hutsteiner/Hutstein records in Warsaw already ?

Thanks a lot
Josef Hutstein

hutstein.org