Setting Column Mandatory based on condition

Hi ,

I have a SharePoint custom list in which I have few columns which have been set as required, when the columns were created. I am trying to add few more columns to existing list and have mandatory conditions based on a dropdown change. Below are new columns:

1) Is Data Required ( Yes / No - Choice dropdown field)

2) User Name ( single line of text)

3) User Start Date ( date only field )

4) User End Date ( date only field )

Please note apart from above columns, I have additional columns which have the required field set in the columns itself. If the value of "Is Data Required" is set to "Yes", then I want to make columns "User Name, User Start Date, User End Date" as mandatory, else non mandatory.

How to achieve this ? I do not have the option of creating a C# code and deploying it.

Thanks