Calendar Template - Category and Users

I am trying to use the Calendar template for an existing application which already has users and categories.
Is there a way to use these existing tables instead of the build-in calendar template table.
Maybe by reassign table and fields like calcalendar fields are reassigned as follows.

$calendarSettings["calendarTable"] = "calcalendar1";
$calendarSettings["calendarKeys"]["calendarid"] = "id1";
$calendarSettings["calendarFields"]["calendarDateField"] = "DateField1";
$calendarSettings["calendarFields"]["calendarSubject"] = "SubjectField"; [/i][/i]