You can use this format to get known properties from an endpoint.
Assuming all the things you listed are actually properties on that computer, your
query would look like this:
((value of results (bes property “Serial Number”, it)), value of results (bes property “User Name”, it), value of results (bes property “RAM”, it), value of results (bes property “Disk Space”, it)) of (bes computer whose (name of it as lowercase = “computername”))