Change port number generated by CONSTRUCT_WD_URL

Question

We are using load balancing and have 2 ports, one of which is open, and other is not (due to security settings).
When our application hits the port that is not open, we are not able to open the application.
Eg: two ports - 100 and 200.
100 is open, 200 is not.
So when WD (due to load balancing) runs on port 200, the CONSTRUCT_WD_URL returns port as 200. The application does not load.
We cannot change the call to the CONSTRUCT_WD_URL method, as it is a standard application that is having it.
What can we do to avoid this issue?
Thanks in adv.

Answer 1

Thanks Xavier. You  brought me very close to the answer.
Now only one trouble is there.
I can maintain entries in the table, and it will take host and port from here.
Port is okay.
But for load balancing, sometimes my host is like this:
abc1234.xyz.com.sg
My actual host which is doing load balancing is : abc.xyz.com.sg
So if incoming URL is like this: abc1234.xyz.com.sg:100, I want it to change to abc.xyz.com.sg:200.
All seems well, but there is this line of code: '
    LOOP AT httpurlloc ASSIGNING <httpurlloc>.
    If specified, match string against (possible wildcard '*' in) table.
      CHECK application IS INITIAL OR <httpurlloc>-applicatn IS INITIAL OR application CP <httpurlloc>-applicatn.
      CHECK for_domain  IS INITIAL OR <httpurlloc>-for_domain IS INITIAL OR for_domain  CP <httpurlloc>-for_domain.
      CHECK host_header IS INITIAL OR host_header CP <httpurlloc>-host.
The last line gives host header as abc1234.xyz.com.sg. So if I maintain my host as abc.xyz.com.sg, it does not go ahead.
I cannot maintain abc1234.xyz.com.sg. Now I am stuck.
Can advise how to go about it?
Thanks in adv.