I used a different approach by creating a linked server. To do it, I followed instructions from this link. Thank you to the author (I couldn't find a...

Got answer on SO. Had to change query as:
WHERE
([table_name].[col1] LIKE ''%' + @var_1 + '%'')
AND ([table_name].[col2] LIKE ''%' + @var_2 + '%'')

SQL that I am trying from report builder:

SELECT
table_name.column1
,table_name.column21
,table_name.column15
,table_name.column6
,table_name.column9
...

Is there a way to check the final SQL query that war run against the database from Report Builder 3.0? I am almost sure that quotes around the parameter is...

I got the solution at http://fuzzy-group.blogspot.ca/2012/04/ssrs-custom-code-to-get-textbox-name.html

In "Text Box Properties" -> "General" -> "Name" I see what I need (that is string "hostname"). I am just not able to define it in expression.

Thank you Sue. It solved my problem. Somehow I didn't notice it and assumed that while passing parameters I can't use "Edit as Text".