It may or may not be possible with WinBatch. But it is impossible to determine that without knowing the protocol being used by your site.
Stayed away from this hoping the OP would come back with error message, or other info to answer Tony's post.
For my part, in last 6 months have had to work with API's/URL's that require:
- standard credentials
- credentials but password as plain text
- username + API token
- user email + API token
- user email + account password
- REST headers and parameters
All that have been worked through communicating with the source, then determining if possible to code.
Perhaps the OP has a situation where credentials are not prompted, or protocol assumed. But be interested in more information.