Expand categories in an embedded view - URL

I have a embeeded view on a form (single cat.)The second column is categorized. When the user clicks on the category I want to expand the category. Normally I do like this:

onClick="window.location='/“+Path+”/CompanyByFT?OpenView&Start=1&Count=999&Expand="+@Text(@DocNumber)

But I don’t want to open the view in the OnClick event, I want´something like this:

onClick="window.location='/“+Path+”/ViewCompanyByFT?OpenForm&Start=1&Count=999&Expand="+@Text(@DocNumber)

So my question is how do I send URL parameters to expand categories in an embedded view.

//Pierre