How to parse a template in footer?

[Kriminal]

I added a right colum to my forums, as it's described here: https://vborg.vbsupport.ru/showthread.php?t=94495

But it's no neccesary you read the thread, it explains how to add a column to the footer, as a table cell.

It's works fine, and it's possible to add a custom template and parse it, as the others. So I put a $custom_template into de right column (the table cell in footer) and add static content... everything works well.
But I can't pass vars into the template, or include other templates ($custom_block1, $custom_block2, etc).
There is no a footer.php, so I can't find the way to add an eval before the output.
I tried to place an eval before

PHP Code:

eval('$footer = "' . fetch_template('footer') . '";'); 


in global.php (line 514) but doesn't work.

So, the situation is the following:
- Added a column in footer template
- Create right_column template
- Added $right_column to globaltemplates array in config.php
- Create a plugin: eval('$right_column = "' . fetch_template('right_column') . '";'); with global_start hook (i tried also global_complete)
- Inside right_column template, I put the static text Hello
- Added after the var $world (so right column template is Hello $world)
- In index.php I add $world = "world";
- Only shows Hello in the right column.

Could you help me to do this?
Thanks in advance,