Corey,

As Aaron shares you will need to script this in Workflow or use the SDK to build a standalone utility or client integration to make this happen.  If you are using Workflow you can make this happen with the SDK Script activity.  You will need to write code to open your XML file and parse out at a minimum the entryID, pageNumber, x and y coordinates, and the width and height of the redaction.

Here is a code snippet that will take the supplied token values and apply a redaction to the specified page;

        Protected Overrides Sub Execute()

            'Try/Catch for any errors...
            Try
                Dim entryId As Integer = Me.GetTokenValue("entryId")
                Dim pageNumber As Integer = Me.GetTokenValue("pageNumber")

                'Make sure the entry supplied is a document...
                If Entry.GetEntryInfo(entryId, Me.RASession).EntryType = EntryType.Document Then

                    'Get all of the necessary token values...
                    Dim x As Integer = Me.GetTokenValue("x")
                    Dim y As Integer = Me.GetTokenValue("y")
                    Dim width As Integer = Me.GetTokenValue("width")
                    Dim height As Integer = Me.GetTokenValue("height")

                    'Instantiate the redaction and rectangle objects...
                    Dim redaction As RedactionAnnotation = New RedactionAnnotation()
                    Dim imageRectangles As List(Of Laserfiche.RepositoryAccess.Common.LfRectangle) = New List(Of Laserfiche.RepositoryAccess.Common.LfRectangle)()
                    Dim newRectangle As Laserfiche.RepositoryAccess.Common.LfRectangle = New Laserfiche.RepositoryAccess.Common.LfRectangle(x, y, width, height)

                    'Get a reference to the page to apply the redaction to...
                    Dim pInfo As PageInfo = Document.GetPageInfo(entryId, pageNumber, Me.RASession)

                    'Add the new rectangle to the collection...
                    imageRectangles.Add(newRectangle)
                    redaction.ImageRectangles = imageRectangles

                    'Add the new redaction to the page...
                    pInfo.AddAnnotation(redaction)

                End If

            'Report any errors to thw workflow instance...
            Catch ex As Exception
                Me.WorkflowApi.TrackError(ex.Message)

            End Try

        End Sub