Dim varstring As String * 6 'fixed length string needed for mid(ansistr,1,3) why 6? 'coz of UNICODE format
Dim start_str As String * 6
Dim wholevarstring As String 'later will redim it
oldstartpoz = startpoz ; ansistr = "" ' init values
Open filename For Binary Access Read Lock Read As #1 ' or use FreeFile(0) for #1 ....
how_deep = 1
Do
Get #1, how_deep, start_str
ansistr = UnicodeToAnsi(start_str)
how_deep = how_deep + 1
Seek #1, how_deep
Loop While (Mid(ansistr, 1, 3) <> "BON") And (how_deep < 800)' or 600
If how_deep > 800 Then
    Msgbox "Couldn't  find Beginning of NOTES!!"
    Close #1
    Exit Sub
End If
startpoz = how_deep - 1
oldstartpoz = startpoz

Seek #1, startpoz
Do
 Get #1, startpoz, varstring
 ansistr = UnicodeToAnsi(varstring)
 startpoz = startpoz + 1
 Seek #1, startpoz
 Loop While (Mid(ansistr, 1, 3) <> "BON") And (startpoz < oldstartpoz + 120) <- just in the case we can't find the EONOTES
If startpoz >= oldstartpoz + 120 Then ' some message 120 lenght of our notes
    Msgbox "Couldn't  find End Of NOTES!!"
    Close #1
    Exit Sub
End If
wholevarstring = String(startpoz - oldstartpoz, " ") ' redim whole string to the size of notes
Seek #1, oldstartpoz
Get #1, oldstartpoz, wholevarstring
ansistr = UnicodeToAnsi(wholevarstring)
ansistr = Mid(ansistr, 1, Len(ansistr) - 1)

at this point the ansistr contain complete NOTES, now we can use some VB's String functions: Split, InStr, InRevStr, Mid, Left, Right ....to get desired values.
Where we would need something like the above? Let say we want to scale some template 3DM file and user want to insert it into Rhino with a predetermined size, so we'll need to know template size and so on ...
Perhaps, one will have some free time and make the above shorter and as a function ...