Thank you very much for your fast reply - that really helped and I was able to install davfs:
univention-install davfs2
now I got the next issue:
mounting manually works fine:
mount -t davfs http:///owncloud/remote.php/dav/files/owncloud/ /mnt/point
but in fstab it wont work:
http:///owncloud/remote.php/dav/files/owncloud/ /mnt/point davfs user,rw,noauto 0 0
I’ve read that I have to type mount /mnt/point to mount the defined folder. Does it mean that I have to insert “mount /mnt/point” anywhere in cron once after booting?