def find_section(lines, MF=3, MT=3):
    """Locate and return a certain section"""
    v = [l[70:75] for l in lines]
    n = len(v)
    cmpstr = '%2s%3s' % (MF, MT)       # search string
    i0 = v.index(cmpstr)            # first occurrence
    i1 = n - v[::-1].index(cmpstr)  # last occurrence
    return lines[i0: i1]