In a certain code language, ‘BRICK’ is written as ‘WMDXF’. What is the code for ‘GOLDS’ in that code language?

$$\left[B\right]    \rightarrow    \left[W\right]\left(difference  -5 \right)$$

$$\left[R\right]    \rightarrow    \left[M\right]\left(difference  -5 \right)$$
$$\left[I\right]    \rightarrow    \left[D\right]\left(difference  -5 \right)$$
$$\left[C\right]    \rightarrow    \left[X\right]\left(difference  -5 \right)$$
$$\left[K\right]    \rightarrow    \left[F\right]\left(difference  -5 \right)$$

similarly "GOLDS" $$  \rightarrow$$ "BJGYN"