how can i apply an expression on a system field

[Anonymous]

hello, I can not apply an expression on a system field, and also how to fix the system fields in a selection list. Indeed when I click on any system field it changes position.

thank you for your reactions

[tresesco]

Could you give a bit more of the context and explain may be with an example?

[Anonymous]

Here are the system fields when I click on the first field it goes to second position and so on is not fixed.

the second figure is the global histogram of all the fields and I would like to click for example on #Satisfaction_client and display its histogram only.

[Anonymous]

Tresesco B, help me please.

[tresesco]

Could you share your sample qvw to look at what you have tried already and what the actual issue is?

[Anonymous]

i cannot share, i use il local.