It is possible in DataDynamic to:

a) manually add labels

b) copy the label-set of one variable to other variables

c) import a complete set of labels from an external file (.txt file).

a) To manually add labels to a variable, in Editor Mode double click over the variable. On the right part of the window, next to the 'Label' box, clicking on the top button with the plus  will add a row in the box, where you can fill in the code (category) and the label. When all the desired categories are added click on 'Save' (small button with disk).

b) You can save labels of a variable to or load labels from Excel from the edit screen. To the right of the labellist, there is a dropdown menu under the bottom settings button that gives access to the "import" and "export" functionality

c) To copy the label-set of one variable to other variables, in Editor Mode first select the destination variables in the variable list, Next click on "Copy labels", in the dropdown select the source variable. Click on "Apply" and the label set is copied across.