Look for the file 'MicroStationVBA.chm' in the installation folder. I have looked at 4 products - and it is there for all 4, in the folders as shown below.
C:\Program Files (x86)\Bentley\MicroStation V8i (SELECTseries)\MicroStation
C:\Program Files (x86)\Bentley\MX V8i (SELECTSeries 4)\MX
C:\Program Files (x86)\Bentley\PowerCivil V8i (SELECTSeries 4)\PowerCivil
C:\Program Files (x86)\Bentley\Navigator V8i\Navigator
C:\Program Files (x86)\Bentley\MicroStation V8i (SELECTseries)\MicroStation
C:\Program Files (x86)\Bentley\MX V8i (SELECTSeries 4)\MX
C:\Program Files (x86)\Bentley\PowerCivil V8i (SELECTSeries 4)\PowerCivil
C:\Program Files (x86)\Bentley\Navigator V8i\Navigator