I was able to approximate the behavior. It's a two grip process instead of just the one.
I added a line that ran the length of the wall and then a constraint Parameter to it.
I started an array from scratch using the array command.
Then I defined two User Parameters. One called Count and one called Mid.
I set Count equal to round(d1/1987.5)+1 this took the distance of the wall and devided it by the distance between the center of the first and second column in your block. Then it rounds it up and adds one. This gives you the total number of columns that will be needed.
I set Mid equal to ((d1-350)/(Count -1)) which is the distance of the wall (minus the end space) divided by the number of columns needed.

I then used Count and Mid in the Array parameters

Now you just drag the wall and then drag the distance parameter.

CADnoob
