Not sure if you can change the export path, but you could create a batch file to run afterwards that moves from the default location to the location you want.
Or if this is a sequence of tests and you have an over writing issue then at the start of the next script run the batch file to move the results from the previous test, renaming it in the process. (You can of cause just use standard VBscripting file copy/move rather than batch files.
Or if this is a sequence of tests and you have an over writing issue then at the start of the next script run the batch file to move the results from the previous test, renaming it in the process. (You can of cause just use standard VBscripting file copy/move rather than batch files.