You can use the Button Text command to change the title of your List Box header programmatically. For example, the code below will change the header titles for column1 and column 2 of a list box.

BUTTON TEXT(*;"Header1";"First Name")
BUTTON TEXT(*;"Header2";"Last Name")

The object name of the header is used in the above code. You can also use the variable name. Check the Button text documentation for more information: https://www.4d.com/docs/CMU/CMU00194.HTM