How to get RSS feed for custom field in post

[Karthick M]

I have a list of post with different category, I am able to generate feed for a particular category,

But I am trying to create a new custom field in post with the option selection box, If the particluar post is get selected with my custom field then the Feed need to generate based on the selection of custom field on that particular post

For Example : I am trying like this : http://mydominain.com /?post_type=post=customfield=rss_feed

[Karthick M]

I found many articles that is related to how to get Rss  for custom post and how to get custom field value in rss field , but i am not able to get the exact thing how  to generate RSS feed for select value of a custom fields in post , Any idea will be more thankful. 

Is this possible to do ?