Magdalena, the answer to the question in your title "...change the value of the parameter..." is NO. This is the #1 fearture request in the Ideas forum.
But I'm not sure that's your real question. If you post a packaged workbook (twbx) with just the geo data and the parameters/filters set up the way you want them I'll take a look. Sounds like there is a solution, I just need to see your situation to work it out.