UCAS application reference as a private candidate

Hi!
I'm trying to apply for university as a private candidate and have got to the reference part. My main concern is the predicted grades section. Since I do a course which is online, my provider says they cannot give the reference on the UCAS application, but only a predicted grades letter signed by the exams officer.
I wanted to know if my old school can enter my predicted grades on the reference on the basis of the letter the provider gave me.
Worst case scenario, nobody can provide predicted grades. In that case, while I do know that the referee can state that I was unable to give them etc etc, do I have a lower chance of getting a place?
Thanks in advance!

You need to ask your old school if they're willing to do this. It's likely they will

They said that they are willing to provide the reference, but they were unsure if they could provide the grades on the basis of the predicted grades letter sent to me by the provider. They can right? Its an official letter signed by the exams officer.

It's at their discretion.
If they're unwilling to provide them in the predicted grades section you could ask them to include a sentence in the reference itself along the lines of "sms96's current online provider has given us the following predicted grades for sms96's pending qualifications: grade grade grade"