Generalized Series Expansions (e.g. AB5-AB9 becomes AB5, AB6, AB7, AB8, AB9)

[snb]

@Rick

I tested only with your offered strings:

1,5,9-12,20-18
1 5 9-12 20-15
1,5 9-12, 20 - 15
AB8-AB12
CD3 - CD7 K4, P2-P5 JM8 - JM3
ABCD1-9
XYZ3 - 7

This doesn't error out on my system however.

Sub tst()
    MsgBox F_expand("a9 - 4 x4,m9 r7 b4 - b8,c4-1")
End Sub

Function F_expand(c00)
  sn = Split(Replace(Replace(Replace(Trim(c00), " -", "-"), "- ", "-"), ",", " "))
  
  For j = 0 To UBound(sn)
    If InStr(sn(j), "-") Then
       c01 = ""
       c02 = ""
       If Val(sn(j)) = 0 Then c01 = Left(sn(j), InStr(sn(j), "-") - Len(Format(Val(StrReverse(Left(sn(j), InStr(sn(j), "-")))))))
       sp = Split(Replace(sn(j), c01, ""), "-")
        
       If Val(sp(0)) > Val(sp(1)) Then c02 = Val(sp(0)) + Val(sp(1)) & "-"
        sn(j) = c01 & Join(Evaluate("transpose(" & c02 & "row(" & sp(0) & ":" & sp(1) & "))"), "," & c01)
    End If
  Next
  
  F_expand = Join(sn, ",")
End Function