Foundation year, with International Experience year?

So I am due to start a Japanese studies with foundation year course this year, it should take 4 years to complete as I will be studying full time.
My Uni offers a version of the course that includes an international experience route which also takes around 4 years to complete. I couldn't initially apply for this as I didn't have enough UCAS points.
I wanted to know if I could complete my foundation year, and then reapply for the international year version of the course?
Would student finance be able to finance a student for 5 years total of Undergraduate? ( 1 Year Foundation + 4 years of study)
The foundation year will cost the standard £9250 of a regular year.
I haven't been to University before, so this would be my first instance of Uni education.
My place is confirmed for my the foundation year version. (4 years)
I have had some mixed responses on this from Uni administration and from tutors and was hoping to get a clearer picture if anyone can help?

TLDR:
Can I take part in an international year, despite my total Uni study time being 5 years at undergrad level?
Would I be able to swap courses in a sense from BA with foundation year to BA with international year once I had completed my foundation year?

:smile: