If the connection is slow, try GNU wget. (manual).
It can be obtained from the web, if not available.

A file selection can be made by filling in the wildcard after the -A option.
To get all fitsfiles of EC063C copy next line to your commandwindow:

wget -t45 -l1 -r -nd http://archive.jive.nl/exp/EC063C_190303/fits -A "ec063c*"

The checksum file can be used to verify the checksum of all datafiles using:
md5sum -c ec063c.checksum (on unix systems).