Just open a Python 3.7 console:

Code:

>>> x=0x0101
>>> hex((x&0xf==1)*0x70f5+(x&0xf==0)*0x2c8c+(x&0xf==2)*0xdde2+(x&0xf==0xf)*0x5967)
'0x70f5'
>>> x=0xde50
>>> hex((x&0xf==1)*0x70f5+(x&0xf==0)*0x2c8c+(x&0xf==2)*0xdde2+(x&0xf==0xf)*0x5967)
'0x2c8c'
>>> x=0x0102
>>> hex((x&0xf==1)*0x70f5+(x&0xf==0)*0x2c8c+(x&0xf==2)*0xdde2+(x&0xf==0xf)*0x5967)
'0xdde2'
>>> x=0xffff
>>> hex((x&0xf==1)*0x70f5+(x&0xf==0)*0x2c8c+(x&0xf==2)*0xdde2+(x&0xf==0xf)*0x5967)
'0x5967'

The formula is

Code:

f(x)=(x&0xf==1)*0x70f5+(x&0xf==0)*0x2c8c+(x&0xf==2)*0xdde2+(x&0xf==0xf)*0x5967

You should learn how and why this works and try to understand the basic code. Its not the solution you are looking for but simply asking for a mapping function with a few points is pretty generic. Without having some white box information or a lot of values or some obvious pattern, my answer could be as good as any.