The language is called CBS (CAPITAL Business Script). It is a propriety language developed by CAPITAL Office Business Software.
All documented calls are found in the VB.CHM help file. Consult the Script Programming section and also Business Functions.
Some (but not all) undocumented calls may still work in V8.
CBS is very loosely based on the xBase language family, Windows Console batch scripting and borrows some ideas from Visual Basic.