Sorry, the classic 2000 is only one program at a time. The feature the XL has to use more than one program is part of what makes it XL....
But......have the two programs you want to use together on your 2000 really got 64 samples using every pad, & do you really need every sample in both programs in your sequence? What you should do is make a brand new program specially for this sequence using sounds & settings you like from other programs.
Start a new program. Assign to pads the sounds you want from your old programs. To make sure you get the same parameter tunings for those sounds do the following
You should already be in PROGAM (SHIFT/6)
Select a program you want to copy a sound's tunings from.
Then go to PARAMS (F2)
In the top line where it lists the program number a selected pad put your cursor onto the pad details. Then OPEN WINDOW, & you get the page for copying note parameters to different pads & different programs.