How to use Collect to push the Host, Source and Sourcetype from the Original index ?

[sagrl]

I want to use the collect command and want to push the Host, source and source-type coming from the Original index.

index=sm sourcetype=mysqld 
| eval host1=host 
| eval index1=index 
| eval sourcetype1=sourcetype 
| eval source1=source 
| collect index="test" source=source1

It is pushing "source1" string instead of its actual value any idea how to send the actual dynamic value ?

[FrankVl]

host, source and sourcetype attributes of the collect command are string attributes, so I don't think you can put field references in there. Doesn't collect retain the existing host and source values anyway? Sourcetype will be changed to stash by default.