RFC to/from SAP: How to change the port?

Dear experts,

to call SAP via RFC the according sapgw<xx> port is used. To what I know this is related to the system number, so if the system number is 01 it's the sapgw01.

Now we need to prioritze traffic over the network which works via ports for us. Is there any way to communicate to SAP via an SM59 TCP destination using a different port than 33<system number>? Like for communications from external application A we use 3301, for application B we use 3302.

Hope I was able to explain it properly.

Regards,

Gunter