Now I have another thing to ask: I don't know how to import the HSK-flashcards into the dictionary. The file shows up on the flashcard, but I cannot access it in the dictionary.
Any ideas? - Thank you.
Go into the flashcard import screen, select "Text File" format, and enter the path to the file on the card in the appropriate field - that should let you import the file into Pleco's flashcard system.