If this is not a particularly changeable workbook (i.e. worksheets are not being added and deleted all the time), you could store the names of the worksheets in a range on a hidden sheet and loop through them by name.
However, it sounds like they are stored consecutively in the workbook so, building on Mathias’ solution, you could use a function to return the indices of the start and end worksheets and then loop through:
Public Function GetStartIndex() As Integer
On Error Resume Next
GetStartIndex = ThisWorkbook.Worksheets("MyStartingWorksheet").Index + 1
End Function
Public Function GetEndIndex() As Integer
On Error Resume Next
GetEndIndex = ThisWorkbook.Worksheets("MyEndingWorksheet").Index - 1
End Function
Sub LoopThrough()
Dim wks As Worksheet
Dim i As Integer
Dim iStart As Integer
Dim iEnd As Integer
iStart = GetStartIndex()
iEnd = GetEndIndex()
If iStart > 0 And iEnd > 0 And iEnd > iStart Then
For i = iStart To iEnd
Set wks = ThisWorkbook.Worksheets(i)
MsgBox wks.Name
Next i
End If
End Sub