Remote operates HDD DVD and DVD/VCR Combo Units

Question

Hello, I recently bought an LG HDD/DVD player, but still wish to keep my old LG VCR/DVD combo unit too for playing old video tapes

Problem is - the new LG remote controls BOTH devices at once.

How can I reprogram something so that the new remote doesn't control the old unit too - can i program each to use a different code?