Just to make sure that I understand the scenario, you have a Lookup List Control that is set to Multiple Selections, and you'd like to (using a Calculated Control) perform a runtime-function "lookup" on the same list as your lookup control is pointing to, but just getting a different column's value (matching the row to the selected items in your lookup control), and summing those values into a single total?

I have exactly the same question . We use a multi select lookup field. I got an array [1,2,3]. On the same list I would like to make a lookup to get a column value of every item of this array. But when I use this array in my lookup function I only get one value of the first lookup.

For example I want to get the country column of every item. I expect from  1,2,3] the values Germany,France,Italy]. But in my test I only get Germany].

Is there an option to make a lookup of every item in an array?

Thanks in advance.