The code below, extract from Debra Dalgleish's Contextures site kinda
does what I want, except for a couple of things,

(1) it extracts to a new sheet, whereas I'm looking 'ideallly' to a
new file
(2) it has listed the manager per row, weheras I associate a number of
locations to set managers and don't have this listed on each row


Option Explicit

Sub ExtractReps()
Dim ws1 As Worksheet
Dim wsNew As Worksheet
Dim rng As Range
Dim r As Integer
Dim c As Range
Set ws1 = Sheets("Sheet1")
Set rng = Range("Database")

'extract a list of Sales Reps
ws1.Columns("C:C").Copy _
Destination:=Range("L1")
ws1.Columns("L:L").AdvancedFilter _
Action:=xlFilterCopy, _
CopyToRange:=Range("J1"), Unique:=True
r = Cells(Rows.Count, "J").End(xlUp).Row

'set up Criteria Area
Range("L1").Value = Range("C1").Value

For Each c In Range("J2:J" & r)
'add the rep name to the criteria area
ws1.Range("L2").Value = c.Value
'add new sheet (if required)
'and run advanced filter
If WksExists(c.Value) Then
Sheets(c.Value).Cells.Clear
rng.AdvancedFilter Action:=xlFilterCopy, _
CriteriaRange:=Sheets("Sheet1").Range("L1:L2"), _
CopyToRange:=Sheets(c.Value).Range("A1"), _
Unique:=False
Else
Set wsNew = Sheets.Add
wsNew.Move After:=Worksheets(Worksheets.Count)
wsNew.Name = c.Value
rng.AdvancedFilter Action:=xlFilterCopy, _
CriteriaRange:=Sheets("Sheet1").Range("L1:L2"), _
CopyToRange:=wsNew.Range("A1"), _
Unique:=False
End If
Next
ws1.Select
ws1.Columns("J:L").Delete
End Sub
Function WksExists(wksName As String) As Boolean
On Error Resume Next
WksExists = CBool(Len(Worksheets(wksName).Name) 0)
End Function