It does not seems simple. You need to have access to website with ftp authentication. I once tried same . I wanted to update a file on my website that will always have the lastesd WAN IP of my network ( a sort of synamic dns updater ).
You will have to look in for command for ftp. For me ( 8 years back ) it was something like this : I used wget to get the latest wanip and then copied it to www
:: *** The path to wget, if necessary (including the trailing backslash):
if exist "%TempFile%" del "%TempFile%"
:: *** Retrieve the html document with the current IP address:
"%wgetPath%wget.exe" %URL% -O "%TempFile%"
:: *** Extract the current IP; this relies strongly on the current format of the source:
for /f "tokens=13 delims=<>: " %%a in ('type "%TempFile%"') do set WanIP=%%a
echo Current WanIP: [%WanIP%]
copy wanip.html wanip.htm