How to incorporate Darcy's raw into Conv-Diff

I would like to incorporate the velocity calculated by Darcy's law into Conv-Diff, how is this possible?
Darcy's law has no variable for velocity, how can I incorporate u=-k/μ<grad p> by Darcy's law into the velocity w of convection-diffusion equation?

You can enter the explicit expressions for the Darcy velocities in the edit fields for u, v, and w in the convection and diffusion dialog box, that is:

  u: -kap_dl/eta_dl*px
  v: -kap_dl/eta_dl*py
  w: -kap_dl/eta_dl*pz

Thank you for your answer.
I was having trouble getting Featool to work because I thought the notation for pressure p was the same as 'edit' of 'Equation'.
It worked fine, thanks.