I might be overlooking something, and not to burst any bubbles of creativity, but I would like to point out that MicroStation's measurement tools can provide what it sounds like you are looking for without any programming. You can do that by:
- Putting the lines you want to summarize the total length for in a Selection Set
- Starting the Measure Length tool
- Clicking a Data point
You can do this with the following series of "key-ins":
mdl silentload selectby
selectby type none
selectby type line
selectby level "Earthing - Proposed"
selectby execute
measure length
xy=#,#
You can also concatenate them together into one "key-in":
mdl silentload selectby;selectby type none;selectby type line;selectby level "Earthing - Proposed";selectby execute;measure length;xy=#,#
(watch word-wrapping... that is all one string) The result in the Tool Settings is the total length of all the lines. The same is true for the other measure tools (e.g. Measure Area, Measure Volume, etc.) If you want to extract the measurement property, you can highlight the result in the Tool Settings dialog and then Ctrl+C to copy that to the clipboard. Or you can also extract the last measured value through VBA by using the MeasureResult1 or MeasureResult2 properties (more information on those is in the MicroStation VBA help).