Related Posts

Hi friends,
Is there anyone here that are using this plugin?
https://fairyfish.net/2007/09/12/wordpress-23-related-posts-plugin/

If yes, I have one question and I dont know if It is possible…
Is possible to make this plugin works without the tags relating? But with posts relating?

For example… I have 2 posts with the same tags, and they appearing like related.
But I dont want them related…
Is possible to choose what posts are relating? For example, puting the id′s of posts that I want in custom fields.

Another example:
X post with ID 49
X post with ID 53

On post with ID 49 I will put ID 53 in custom field and vice-versa.
And in the end, they appear as related.

Is possible, how? ??

Someone understood what I am trying to say? Sorry for my poor english ??