How to add two Property to a project file with same name?

Hi,

I'm trying to add two Property to a project file with same name from code, the expected result like below.

<MyProperty>testvalue</MyProperty>

<MyProperty Condition=" 'MyProperty' == '' ">testvalue2</MyProperty>

I'm using Microsoft.Build.Evaluation.Project.SetProperty method to add the new property. However, this method only can add or override a property method, so not able to add duplicate properties with same name.

Could you please tell me how to achive this?

Regards,