Javascript link to %userprofile%/My Documents/example.pdf does not work

I want to create a Javascript link to %userprofile%/My Documents/example.pdf (e.g. C:\users\<username>\My Documents\example.pdf)

The opening of the file is done with following script:

var Path = "%UserProfile%/My Documents/example.pdf";

app.openDoc({cPath: Path, oDoc: this,});

This results in following error:

NotAllowedError: Security settings prevent access to this property or method.

Any idea how I can get the link to run?