Xquery declare an external variable

[FredInWV]

I have an xquery file with the following line of code:
declare variable $PolicyFile as xs:string external;
I'm running OxygenXML Enterprise editor ver 8.0
When I run my xquery, I get the following error:
Severity: error
Description: No value supplied for required parameter $InputTWPolicyXMLFile
How do I tell OxygenXML what $PolicyFile is? How do I input the string that tells OxygenXML what my external variable is?

I have looked throught the user manual, I've searched the forum, and I've Googled on this. I cannot find an answer. Is there a simple solution?

[FredInWV]

I apologize. I have OxygenXML Enterprise ver 12.0. I was thinking of a different applications.

[adrian]

Hello,

Edit the transformation scenario(Document -> Transformation -> Configure Transformation Scenario, Edit), press the "Parameters" button and you will see a dialog with the detected parameters. "PolicyFile" should already be listed there, you just have to Edit it and specify a value.
If it's not there for some reason simply Add it.

Regards,
Adrian