How to print PDF to different trays

HI,

We have a Konina Minolta Bizhub C224E and we want to print pdf's to it using different trays.

We make a batch with a lot of reports, each report has the same number of reports :

1     letter

2     portfolio

3     invoice

But not al reports are of the same length of pages.

So when we create the reports we have to add a pdf code so that the printer knows from which tray he has to use.

1 Letter, first page tray 3, second and third page tray 2

2 Portfolio tray 1

3 Invoice tray 3

Does anyone know what kind of code we have to use to arrange this ?

Thanks in advance.

Jeroen