you can edit the transformation and in WebServices Consumer Properties tab update End Point URL field.
Please, let me know if this works for you.
If I understand your use case properly, you are looking for a way to "dynamically" adapt your WSC transformation, without having to edit it manually or re-creating it from scratch for any new scenario.
There are options to dynamically change the endpoint URL. You can do this by creating the WSC transformation with a URL port, and then pass the URL on to that port from a previous transformation (e.g. EXP). You can also use a parameter file and define a session parameter that will be used in the WSC connection object (i.e. instead of hard-coding the URL).
Changing the ports is a different thing. This means your contract (i.e. WSDL) with the WS provider has changed. Moreover, such changes also affect other transformation up/down in the pipeline. I cannot think of any feasible way to achieve this in PowerCenter. The Developer Tool (i.e. IDQ, DEI) supports a feature called "dynamic mapping." I'm not sure whether something like this would help in your scenario. Such feature is not available in PowerCenter, though.
Thanks! Paolo for your knowledge sharing.