Sub DeleteTextBetweenTwoWords()
Dim strFirstWord As String
Dim strLastWord As String
Dim objDoc As Document
Dim lngPara As Long
Dim oRng As Range

    Set objDoc = ActiveDocument
    strFirstWord = "T:"
    strLastWord = "P:"

    With Selection
        .HomeKey Unit:=wdStory
        With Selection.Find
            .ClearFormatting
            .Replacement.ClearFormatting
            .Text = strFirstWord & "*" & strLastWord
            .Replacement.Text = strLastWord
            .MatchWildcards = True
            .Execute Replace:=wdReplaceAll
        End With
    End With

    For lngPara = objDoc.Paragraphs.Count To 1 Step -1
        Set oRng = objDoc.Paragraphs(lngPara).Range
        If oRng.Words.Count > 50 Then
            oRng.MoveStart wdWord, 50
            oRng.Collapse 1
            oRng.InsertParagraphAfter
        End If
    Next lngPara

    Set objDoc = Nothing
    Set oRng = Nothing
End Sub