The answer that the Wizard gave is still correct. You are using OpenVMS, which means that there simply are not examples of every call in every language. What was available of for programming examples for OpenVMS largely disappeared off the net a decade or more ago, unfortunately. This means learning the OpenVMS calling standard and argument passing, and how that applies to this and other calls (call by value, call by reference, descriptor by address, etc), and how to use examples of one call for some other call. Other example calls from usenet newsgroups such as comp.os,vms, or from the OpenVMS Freeware, or elsewhere.
Here, you can also translate an application-specific logical name — not my favorite approach — or can read the IP address from a data file, and bypass the problem.
For this case, using the OpenVMS APIs? Fortran isn't going to want to call gethostbyname() call directly either, as that call returns a pointer to a structure. Fortran pointers differ somewhat from how C pointers work. (Might also need to call the CRTL initialization routine decc$crtl_init call here too, if you're heading down that path and planning to use jackets and calls into the C RTL from an application with a main program written in a language other than C.) Which means you're either going to be using $qio calls (e.g. see 2.16.2 for the general sequence, though that example is in C, and also see some of the old discussions from comp.os.vms newsgroup) to get the data from TCP/IP Services, or you're going to be using a wrapper around the C call to dereference and pass the data to the Fortran code. (There are examples of the latter approach posted.)
FWIW, consider avoiding the IPv4-only gethostbyname() and gethostbyaddr() calls in any new code. The getaddrinfo() and getnameinfo() calls are the preferred approach in new code. (While OpenVMS does now have these two C calls and related baggage, there are wrinkles, and unfortunately there does not appear to be any documented $qio function code associated with these.)
If you're just starting to learn IP networking, there are available resources.
The comp.os.vms usenet newsgroup gets more traffic than this place, too. To access that usenet newsgroup, you can either use Google Groups (a front end which has its own issues, but the search usually works) or scrounge a newsreader for your preferred local operating system and register for a free Usenet account from one of the various providers, such as Eternal September.
