Using this formula in cell C2

=REPLACE(B2,FIND("B",B2),LEN("B"),"C")

gives the result of C (in C2) if theres a B (in B2)

I also want to get a result of D in C2 if theres an I in B2 so

=REPLACE(B2,FIND("I",B2),LEN("I"),"D")

Both work separately but can't figure how to nest the 2 functions together

help please - or is there another easier way to get the same result?

many thanks
Jon