I'm having trouble finding some kind of secondary source to learn about Polish knights (from Polish knights Hospitallers, or Order of Malta) who took part in the Crusades to the Holy Land.
I took a quick look, there were many crusades
The specific crusades to restore Christian control of the Holy Land were fought over a period of nearly 200 years, between 1095 and 1291.
The Wendish Crusade (German: Wendenkreuzzug) was an 1147 campaign, one of the Northern Crusades and also a part of the Second Crusade, led primarily by the Kingdom of Germany inside the Holy Roman Empire and directed against the Polabian Slavs (or "Wends").
So maybe Poland was not part of the crusades to Jerusalem?
I would have to read more about it but this is a very interesting topic, nice one.
Polish order (founded in Poland) was the Order of Dobrzyn
The Order of Dobrzyń... was a military order created in the borderland of Masovia and Prussia (today's Dobrzyń Land, Poland) during the 13th century Prussian Crusade to 'defend against Baltic Prussian raids'.