Scanavos, if you post one-line questions you are not going to get useful answers!
On any forum, you have to put some effort into writing the question, if you want to get anything useful out of it.
Are you going VFR or IFR?
If
VFR, it is a case of obtaining the VFR charts, laying them out all over the floor and drawing lines on them. Jeppesen sell 1:500k VFR charts, all the way down to Italy.
If
IFR, then you need to work out a valid Eurocontrol route, e.g. this FL100 one
EGKK DVR L9 KONAN L607 ULMEN DCT NASBO Q762 FRANK Z12 RINEX W718 DKB G5 AKANU L603 TEGBA L605 GAMLI L725 SNU M138 PUBEG M725 ZAG L187 DBK A48 BRD DCT LIBR
but at 1175nm you won't be flying this in a C172
unless you have a ferry tank. The aforementioned route was worked out in a few seconds using
this tool.