Fix/wall and fix NVT with different time steps

Dear LAMMPS users

I would like to simulate a box which includes N particles. The interaction between them is based on "Yukawa potential" and also I have the fix wall with "1/(r^256)" potential.
for this simulation I would like to use different time steps:

dt1 = 0.5 for "Yukawa"
dt2 = 0.0001 for the "1/(r^256)"

But I could not find out how can I do that.

SO would be grateful if one can help me with that.

Best regards
Moji