Let's hope, he has NOT converted/transcoded from mp3 source to flac,
but better he has ripped his flac files directly from CD (best way like described at
http://www.high-quality.ch.vu imo).
So to answer his question,
several possibilities:
1. connect digitally your PC with your HK/amp, hopefully it has digital in.
Your PC should have soundcard which does not resample internally eg. 44.1 to 48 kHz, but optical or coaxial digital out.
2. if no digital connection possible, connect via analogue cables your PC to amp.
3. decode flac to wav and
burn Audio-CD, or CD-Extra, Nero will do fine.
There's even flac plugin for Nero to drop flac files directly into Nero, or use the Burrrn,
or maybe even EAC as writer.
The recommended software player/decoder for 1. or 2. (or 3. decoding flac->wav) is foobar 2000 , or winamp, or, or...
(lol, soemhow only minority of posters here have answered his questions with these striking and simple answers, but quite a big number of posters took the negative interpretation of what he wrote...
edit:
reading his 2nd post in context, it could really lead to the understanding, he transcoded mp3-128 -> flac

, though i believe, he wanted to express, he is converted in his mind, to encode to flac instead of mp3, hopefully, hm..)