It's possible to do that using the http function of Lapper.
I have this in one of my scripts:
This will send data from Lapper to the mentioned PHP file on a webserver.
Retrieving the data by the PHP-file looks like this:
### Get data send through LFS Lapper ###
### End ###
Then you can do what ever you want with it.
In return you can make PHP do something in Lapper as well, see this example:
echo "cmdLFS(\"/msg ^1WARNING: ^7You are using a proxy!\");";
This will send a message within Lapper, but you can also make buttons popup or be closed or what ever you like.
The possibilities are nearly endless.