Flexible Concatenation Function

[snb]

or ?

Sub ConcatDashedRanges()
  Columns(1).replace "=","'="

  For Each Ar In Columns(1).SpecialCells(2).Areas
    Ar(1).Offset(, 1) = Application.Trim(Join(filter(filter(Application.Transpose(Ar.Value),"--",false),"'=",false), ";"))
  Next
End Sub

[Rick Rothstein]

or ?

Sub ConcatDashedRanges()
  Columns(1).replace "=","'="

  For Each Ar In Columns(1).SpecialCells(2).Areas
    Ar(1).Offset(, 1) = Application.Trim(Join(filter(filter(Application.Transpose(Ar.Value),"--",false),"'=",false), ";"))
  Next
End Sub

Your code does not appear to include the cells that started with the equal sign within the concatenated output from the macro (at least on my tests it doesnt').

[snb]

That's correct; they have been filtered out.
You can remove the filter that does that: filter(...,"'=","")