This function does not seem to exist in ANVEL 2.5, i.e. when I try to invoke it from the built-in Python console, I get an error message saying AttributeError: 'module' object has no attribute 'GetObjectIdFromAssetId'. Other Anvel.Assets functions are there.
Please note that the wiki has been updated for ANVEL 3.0. If you'd like to reference the 2.0 documentation, check out http://wiki.anvelsim.com/2/index.php/ANVELCommands#Assets