Hi Prem,
thank you for your reply and I did some investigation about the report RSQIWKEX. This report (see SAP Note 1621492) is used to reset any inbound queue in error state so that it could be re-processed by the inbound queue scheduler.
In other words this might be not the best way to give these queues a higher priority. Anyway you write that the report is picking up all queues (which are named as defined in the variant of the report e.g. ISP*) and sets the status to runnng status which would mean that they are prioritized as you described before. But I could not find any hint in all SAP Notes as SAP just describes that the status will be reset and not set to running status.
Do you have any more hints here?