1st problem i see is that you are on the 3rd floor - wiring starts at an external box at ground level usually facing the road - that box is wired back to the street cabinet - if yours is the only VM install in the flats then that will or should have been done already
there is usually one external box per customer but on flats they can and do share the external box so maybe thats the plan here
from that external box they usually go up the external wall and trough it to an internal point - that would be where the drilling comes
but going back to my comment that there may be a problem with you being on the 3rd floor - whilst they normally drill from the inside i believe and could feed the wires from the inside they would not be able to clip the wires to the external wall as they do not carry ladders to get to that height so it might be slightly untidy
all that assumes there is an existing external wall box for other installs in the building
some flats are installed from an internal comms cupboard - if thats the case here then any drilling will be through internal walls
you really need a bit more info as to what exists and/or if there are other VM installs in the building
____________________
Tony.