echo 'a,b,"cc,dd,ee",f,ii,"jj,kk",mmm' | \
  awk -v sep='"' '{
         for(i=1;i<=length($0); i++)
         {
            ch=substr($0,i,1)
            if(ch==sep) {inside=!inside}
            if (inside && ch==",") {continue}
            printf("%s",ch)
         }
         printf("\n")
       }'