I agree with ADT that
Maciej (pronounced mAh-chay) is the Polish coloquial form of Matthias/Matthew. The Polish literary form of that name is
Mateusz (pronounced mah-tAY-us).
I know too little about Lithuanian names but anyway, the name Mycholas (perhaps
Mikolas, Polish Mikola) seems to correspond to Nikolaus/Nicholas rather than to
Michael.
The corresponding Polish name for
Michael is
Michal (pronounced mEE-xahl). Most probably, its Lithuanian corespondent is Michalas.
I cannot imagine the Lithuanian correspondent of Matthias/Matthew/Maciej.