Reassign Parameter setting from Ancestor

[Mario Sacco]

Is there a way to reassign all the parameters setting of a large set of objects from their ancestor?
I tried without success using "LP_XMLConverter fixhierarchy"

Now to do that I need to make it one by one with three steps: [list=]

change the subtype with a general subtype
delete incorrect parameters
reassign the correct subtype.

Is there a quicker method?
I suppose Graphisoft don't make it one by one for theirs widows.

I'm making that for our Parametric Plants by ArchiRADAR.

Thank you