setValue in 2.6.4 with variables that have a dot in their name

A form is submitted with the following form field names:
field1
field2
new.field1
new.field2

They go into the event collection correctly (i.e.,
event.getValue('new.field1')), but Im not able to change that value in
the event object using setValue.

event.setValue('new.field1','new value') puts "new" in the event
collection (which would be a structure containing the one key,
"field1").

How can I modify the value of this element in the event object using
setValue?

Tim

Following up on my own post.

event.setValue wouldnt work because of the dot in the key name.

However, this works:

structInsert(arguments.event.getCollection(),"new.field1",mynewvalue,true);

Hope that helps somebody--

Tim