Signals Notebook: Parsing parameters in URL string

We would like to use the external action functionality of Signals Notebook to invoke an external action. In general the GET external action functionality would fulfil our needs, i.e. parameter specification / handover via the URL. However, the application we need to call requires specific key words between the "?" in the URL and the input parameters (http://<server-address>/<Path>?exec&pm:<InputParameters>). Unfortunately, I found no way to specify this in the external action setup. When I enter http://<server-address>/<Path>?exec&pm:

into the URL field of the Edit External Action Dialog of the System Configuration Portal, the input parameter specified in the “Parameter Name" and "Apply To" fields are directly added to the URL after the "?" and the rest of the URL is cut-off.

Is there any way to prevent this? Specifying the exec&pm: part of the required URL before the parameter name in the “Parameter Name” field does also not work, since & and : are not allowed to be part of the parameter name.

A:

To implement this would require to modify the product itself and this is only possible if the Product Management agrees to it.
A temporary solution could be a Javascript that modifies the URL into the required format on-the-fly.