From the GUI you cannot extract multiple columns from a shared queue but you can do that using a Javascript.

You can use the "split" function to achieve your goal.

For example, let's say you consume your first row from your shared queue into the "foo" variable.

var list = context.variableManager.getValue("foo"); //Get the content of my foo variable

var MyArray = list.split(','); //we use "," as separator for your columns from your shared queue

From here, MyArray[i] will contain the value i.

Then you can put your values into  "Customer_i" NeoLoad variables with a for loop.

var index;

for(index = 0; index < MyArray.length; index++) {

    context.variableManager.setValue("Customer_"+index,MyArray[index]);

}

From here the "Customer_i" variables contain the values of all your columns.

As you understood, that methods means that you have to consume all the columns of your row more or less at the same time.