If I recall correctly you only need the 5 hours night for CPL issue. You don't even need the 'qualification' in your licence, just do 5 hours at night.
I'm afraid that you do not recall correctly. Paragraph 11(b) of Appendix 1 to JAR–FCL 1.160 & 1.165(a)(4) states
"Applicants [for the CPL(A) course] without a night flying qualification aeroplane shall be given additionally at least 5 hours night flight instruction" Consequently, if you do not hold a night qualification when applying for the course, you have to do an additional 5 hours on the course.