Hi, not all of us involve in the same career like yours
need to explain quantity? or total length? http://www.lee-mac.com/lengthfield.html
or this link :
1.select partial text value & lines (eg: start at column 4 to 13 ) export all to EXCEL
2.apply formula in EXCEL is much easier
3.copy paste back the result back to ACAD
p/s: post example before & after
I'm not sure that I fully understand your requirements, or why you wouldn't read the clipboard content directly, but perhaps issuing (textscr) to switch focus to the command-line prior to issuing the getstring prompt may offer the solution you are after.