Is it possible in Creator to write a Deluge script that will over write data in a field in the parent with up dated data from the mirrored field in the child?

I am bringing in data, from a lookup, into the child record. I have created mirrored field names in the child form and the lookup deluge script functions as expected. 

If the data changes in the 'Remarks" field of the child record I would like to over write the data in the "Remarks" field in the parent on save and on edit...

How best to accomplish this?

Thanks