Excel VBA Dynamic Ranges - vba

Question

I'm looking to improve my code to dynamically set ranges where data exist instead of hard coding the values. The starting value of the range will never change, but the ending value will if more month columns are added. What is the best way to approach this. Would be easier to make the range user defined?
Here's what I have:
The code will split data by unique group name starting at C5 into separate worksheets.
Public Sub Splitdatatosheets()
' Splitdatatosheets Macro
Dim Rng As Range
Dim Rng1 As Range
Dim vrb As Boolean
Dim sht As Worksheet
'Find unique value for splitting
Set Rng = Sheets("Sheet1").Range("C5")
'Find starting row to copy (Re-code to dynamically set)
Set Rng1 = Sheets("Sheet1").Range("A5:M5")
vrb = False
Do While Rng <> ""
For Each sht In Worksheets
If sht.Name = Left(Rng.Value, 31) Then
sht.Select
Range("A2").Select
Do While Selection <> ""
ActiveCell.Offset(1, 0).Activate
Loop
Rng1.Copy ActiveCell
ActiveCell.Offset(1, 0).Activate
Set Rng1 = Rng1.Offset(1, 0)
Set Rng = Rng.Offset(1, 0)
vrb = True
End If
Next sht
If vrb = False Then
Sheets.Add After:=Sheets(Sheets.Count)
ActiveSheet.Name = Left(Rng.Value, 31)
'Copy header rows (Re-code to dynamically set) to new worksheet first cell
Sheets("Sheet1").Range("A4:M4").Copy ActiveSheet.Range("A1")
Range("A2").Select
Do While Selection <> ""
ActiveCell.Offset(1, 0).Activate
Loop
Rng1.Copy ActiveCell
Set Rng1 = Rng1.Offset(1, 0)
Set Rng = Rng.Offset(1, 0)
End If
vrb = False
Loop
End Sub

Answer 1

Here's the updated code for anyone who stumbles across this question.
Public Sub Splitdatatosheets()
' Splitdatatosheets Macro
Dim rng As Range
Dim Rng1 As Range
Dim Rng2 As Range
Dim vrb As Boolean
Dim sht As Worksheet
Dim R_Start, R_End, H_Start, H_End As Range
'Set Header
Set H_Start = Cells(4, 1)
Set H_End = H_Start.End(xlToRight)
'Set Data range
Set R_Start = Cells(5, 1)
Set R_End = R_Start.End(xlToRight)
'Find unique value for splitting
Set rng = Sheets("Sheet1").Range("C5")
'Find starting row to copy
Set Rng1 = Range(R_Start, R_End)
Set Rng2 = Range(H_Start, H_End)
vrb = False
Do While rng <> ""
For Each sht In Worksheets
If sht.Name = Left(rng.Value, 31) Then
sht.Select
Range("A2").Select
Do While Selection <> ""
ActiveCell.Offset(1, 0).Activate
Loop
Rng1.Copy ActiveCell
ActiveCell.Offset(1, 0).Activate
Set Rng1 = Rng1.Offset(1, 0)
Set rng = rng.Offset(1, 0)
vrb = True
End If
Next sht
If vrb = False Then
Sheets.Add After:=Sheets(Sheets.Count)
ActiveSheet.Name = Left(rng.Value, 31)
'Copy header rows to new worksheet first cell
Rng2.Copy ActiveSheet.Range("A1")
Range("A2").Select
Rng1.Copy ActiveCell
Set Rng1 = Rng1.Offset(1, 0)
Set rng = rng.Offset(1, 0)
End If
vrb = False
Loop
End Sub