You can log all of them and they all count. It doesn't say anywhere that the hours from a ppl have to come from a school in either the UK or in JAR land for that matter, nad being P.u/t is being P.u/t, regardless of when and where it was. These hours never 'expire'.
Having said that, it would become tricky if you needed those hours to make up the 45 to get your PPL issued. You'd now need proof that you have flown them, otherwise the school might not sign your completion of training thingy on the form.
You will most likely do more than 45 hours on your PPL course (99.9% of students do), so you won't be 'needing' those hours to get your minimum required number. Therefore, no problem.
Good luck.
Gerard