function! C2nim(l1, l2) abort
  let name = tempname()
  echo name
  call writefile(getline(a:l1, a:l2), name)
  exec a:l1.','.a:l2.'delete _'
  call system('c2nim '.name)
  let result = readfile(name . '.nim')
  -1put =result
endfunction

:command -range C2nim call C2nim(<line1>, <line2>)