How to set the web app's site number to a public property?

[AceBear]

In a project, I would like to dynamically set the Site Number of a website. I did the following steps to attempt to achieve this, but it keeps giving me error during installation:

1) I add the web site "APOC" under the Server Configuration/Internet Information Service/Web Sites. 

2) I created a property "PS_WEBSITENUMBER" in Behavior and Logic/Property Manager and set the value to be 0.

3) I set the {PS_WEBSITENUMBER} to be the value of the site number of "APOC".

The installation builds fine but an error was threw during installation.  

[banna_k · Accepted solution]

Hi @AceBear ,

  try giving using square bracket:

3) I set the [PS_WEBSITENUMBER] to be the value of the site number of "APOC".

[AceBear]

Thank you. This works.