The apparent ambiguity is resolved with sheet property specification of the model in focus (see listbox, lower lefthand corner of SHEET PROPERTIES dialog with heading 'Use custom property values from model shown in:').
allowing the Note specification: 'Weight: $PRPSHEET:"Weight"'. See 'Link to...
The API evolves (sometimes varying by Service Pack) reflecting changes to the SW Object Model; precise answer to original question requires system specifics.
As of SW2003 SP2R11.0 Density is part of MassProperty object; System units are Meters, Radians, Grams, Seconds .. Property UseSystemUnits...
You'll have to interrogate the object model (that is, use the API) to do what you want automatically. Check the APIHELP.CHM file, ModelDoc2::GetUserUnit and SetUserUnit.
If SW2K5 continues to accomodate VBA, and you have Excel, then you will still be able to use Excel via macros. See VB GetObject and CreateObject functions.
You can include a driven dimension in Design Table. SW2003 does not accept add via double click, which means the value must be entered as result of an Excel calculation. For live update this implies all controlling variables must also be in the design table. Don't know if 2004 will permit dblclk...
The sketch has relations (constraints) which are no longer valid as a result of one or more model changes. Open the sketch (from either the part file or edit part within assy if needed), select one of the flagged sketch lines, select 'Display/Delete Relations' (the eyeglass icon). Dialog will...