How to update user detils using macro..?

There is not such functionality out of the box. You can implement custom macro (see documentation), but the purpose of macro is getting data, so updating data with macro is not recommended approach.

so can u please tell me some another method to update data..

There are any. In your particular case I'd use MyProfile web part in conjunction with an alternative form for user. You can configure or build appropriate form in Modules -> Membership -> Classes -> User (or UserSettings) -> Alternative Forms. There should be some predefined forms, so you can use them as example.

Hello Roman,

----Happy New Year--------

Actually my question is that there is a Points column in user table and he purchased some items now his points is like New_Points=Points-Items_Price. now i have to update New_Points with existing Points. so how can i solve it...

I'd override AddShoppingCartItemInternal method of the ShoppingCartInfoProvider - this is probably the best way to do, what you need.

You can find some inspiration here:

• https://docs.kentico.com/display/K82/Customizing+providers
• https://docs.kentico.com/display/K82/Custom+Info+provider+example
• https://docs.kentico.com/display/K82/Customizing+application+of+Buy+X+Get+Y+discounts

Assuming you have the EMS version with online marketing,you may be able to use automated marketing and set up a process that will capture this and add the value to the user/contact. It would be worth looking into because you wouldn't have to custom code anything, plus, you could modify it and create others that run in parallel. If you don't have the EMS version, then Romans method will work and be a pretty simple implementation.