Converting an Excel Diffusion Model to Matlab

I am attempting to recreate a diffusion model from Excel in Matlab. The Excel model had a large spreadsheet where concentrations could be calculated by looking at the values in adjacent cells and in previous timesteps. I have recreated this in Matlab, but it is a static model. In Excel, I was able to use solver to adjust a few input variables to calibrate my model. I see that Matlab is capable of performing solver functions, but I’m not sure how to iteratively calibrate my model, since it appears that I will have to have Matlab recreate the model in each iteration. Any general guidance on how to approach this would be appreciated.

What I currently have in Matlab is a function that accepts input variables and yields a massive matrix with concentrations at different depths over many timesteps. I would like to use a solver function to determine which input variables yield an output matrix that best matches measurements I have for specific depths at specific times.