Enable Custom Site definition on feature activation

Hi All,

I want to enable my custom site definition only on activating feature.

For example:

I have created new custom site definition called "SampleTemplate" under Sharepoint customization categories. Once it is deployed as Farm solution, the template is available for all Web application in entire farm server like team site template, publishing template,etc.

But my requirement is that I want to make my custom site definition to be available / visible under "Sharepoint customization" categorties only when I activate particular feature  in my site collection / web application.

I am unable to achieve through feature stapling, custom feature definition or event recievers ? Any one can suggest on this.

Thanks in advance!!!!

Regards,

Subbu