Armoured Cat5e is constructed of a standard Cat5e cable with a layer extra insulation over the top, that is followed by te steel armouring and then an outer sheath.
Get a 100x100 adaptable box and feed the SWA through a gland and into the box. The armouring stops at the gland so inside you will have Cat5e and the extra insulation layer. Get a Cat5e junction box which has 8 pairs of IDCs and terminate into that, keeping the box inside the adaptable. The internal Cat5e comes through a smaller gland and joins up.
All looks nice and neat - you could do away with te adaptable box, however it will look untidy.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
M H C
taurus excreta cerebrum vincit