Option Explicit

Function Test(FReg As Range, FStr As String) As Range
Dim ResR As Range, sAr As Range, firstAddress As String
With FReg
  Set sAr = .Find(FStr, LookIn:=xlValues, LookAt:=xlWhole)
  If Not sAr Is Nothing Then
    firstAddress = sAr.Address
    Do
      If ResR Is Nothing Then
        Set ResR = sAr
      Else
        Set ResR = Union(ResR, sAr)
      End If
      Set sAr = .FindNext(sAr)
    Loop While Not sAr Is Nothing And sAr.Address <> firstAddress
  End If
End With
Set Test = ResR
End Function

Sub Test1()
Dim a As Range
  Set a = Test(Range("A1:C10"), "A")
  If Not a Is Nothing Then a.Select
End Sub