represent in regulaer expretions

Question

ineed to do that in windoesform using regex
the input form like this
f(x,y,z)= x+y.(z.y)
in the first i need to take the (z.y) and replase by any symbol (k1) and then takt  (x+y) and  replase by (k2)
then  the final  out of  f=k2.k1