Adding a block on the main page right column

[CoolHandLuc]

I need to add a block of information that I need to query prior from the database.

I made add-on stand alone but never add to include a box on the right.

Where do I put the PHP code to query the database and fill in the variable?

In which template do I put the HTML code with the var so it show on the right column of the main forum page?

How do the main page know how to execute the PHP code?

For the rest I already have the PHP logic written and want to pass one variable that will be the whole box content. It's just how to place things in VB that I am not familiar. I already coded a add-on so I know how to get the data.

If a article exist, please point me to it. I just could not find this.