Public Sub Convert_To_Hyperlinks()
    Dim Cell As Range
    For Each Cell In Intersect(Selection, ActiveSheet.UsedRange)
        If Cell <> "" Then
            ActiveSheet.Hyperlinks.Add Cell, Cell.Value
        End If
    Next
End Sub

http://www.jerryleventer.com/excel-tutorial-how-to-convert-plain-text-links-into-hyperlinks/

Save the following code as a macro and then apply it to the fields you want to convert

Convert Excel plain text links to hyperlinks

excel

Visual Basic