Hi Patrikc,
Do you want to show the form without losing the grid focus? If so, Please refer to the browser samples \In depth\DropDownFormAndUserControlSample shows how you can popup a Form from a grid cell. Below are the forum threads that discuss with similar issue.
Forum 1:
http://www.syncfusion.com/support/forums/message.aspx?MessageID=48111Forum 2:
http://www.syncfusion.com/support/forums/message.aspx?MessageID=51392Best regards,
Haneef