hmmm...seen this post somewhere else...so you may see the same reply i gave there!!!
if you can get bbc2 then you will get c4 on 104..if not then your dish may be just too small or need realining
bbc2 and c4 are on the weaker horizontal frequencies, whereas c4=1 is on the stonger vertical frequencies
of try to add channels on 12480 and select c4 from that list....it may not be available during late afternoon / early evening in your area, but its a start