Hi NBS community

I am running an analysis were I want to control for age.
My study design has 2 groups (controls and patients) and 2 time points (two-way repeated measure ANCOVA).
I hypothesized that the influence of age on the controls is different from that on the patients. I was wondering, if the design below is correct to control for the influence of age on each group separately.
What about setting up that part of the design matrix which models the covariate in NBS like this (in the example I put 3 subjects per group):
...... Age Patients Age Controls
...         34                0
....        53                0
....        23                0
....         0                30
...          0                51
...          0                22
Technically it works, but I don't know if it is correct.

Thank you in advance for any kind of advice.
Kind regards
Patrizia