Only products covered by harmonised standards (or equivalent for the United Kingdom) can be CE (UKCA) marked.
In EN 15408:2007 version, only products under EN/ISO standard can be subject to CE (UKCA) Marking.
DIN standard is a German national standard and unless it is an international/European standard (EN/ISO) and approved by the European Union (or separately by the United Kingdom under UKCA marking) as a part of harmonised standards, it cannot be used for CE (UKCA) marking purposes.
In the new release of EN 15048:2016, a limited number of products can be offered as CE (UKCA) Marked to the national standard like DIN or BS.
Currently, EN 15048:2007 edition is the only harmonised standard that can be used for CE (UKCA) marking.