They're not recognised as qualifications in Poland, so they won't be useful. They also won't accept them for university entry.
Some institutions do accept them (they're NARICS Band 7) however the nearest Polish equivalents (which are relatively rare) tend to be in engineering/technical subjects rather than computing.
If the admissions tutor is worth their salt, the person should be able to get on a course; HNC is at a higher level than Matura, however in PL they prefer the theoretical to the practical (not done well there) and it is easier to start in Y1 of a course.
