How do I add a column (new feature) to the subset matrix (chosen rows) in the optimal design function?

[#1]

I am doing optimal design. I have 57 runs that represent the locations of sensors. There is a factor called the Penalty factor. (not a constant factor) that is calculated based on the distances between the sensors (each sensor represents a row in the matrix). This factor should be updated after each iteration. I need to calculate the penalty factor only of the subset rows "chosen rows" (for example, 20 in my problem). The distances are expressed in a separate worksheet. 

I hope my problem is clear enough! Please, let me know if there is any question!

[#2]

I am concerned that the Penalty factor depends on the sensor location factor, so that that combination will produce a singularity in the regression analysis.

Please provide a picture of your design for the locations and how the Penalty is calculated.