How to use Element Text functionality in WebUI tables?

I need to mask my indexes names in WebUI tables the same way is possible to do in WinUI pivot tables using an string parameter.

How I can do it?

Example:

Set Frubas := { '1', '2', '3', '4'}
Ps_DescriptionFrubas('1') := "First"
Ps_DescriptionFrubas('2') := "Second"
...

In my WebUI table it appears as 1, 2, ... and it should appear "First", "Second" ...