I have defined ten load cases. Now I want to add two more load cases right after the third load case. Is this possible?
Yes, it is possible. To do this, select the menu "Tools" -> "Renumber" -> "Shift."
You can adjust the numbering of the load cases in the Load Cases and Combinations section (see figure). Here, you can specify the numbers of the load cases that you want to shift in order to create a gap. Use the Increment column to specify the size of the gap.