The best way to do this is to use the Outlook document inspector to access the message body and then the process is much like programming in Word VBA. However in order to do this, it is necessary to open Outlook correctly and your code won't do that. Use instead the function from http://www.rondebruin.nl/win/s1/outlook/openclose.htm to open Outlook, which the code below calls.


Private Sub CommandButton21_Click()
'Graham Mayor - http://www.gmayor.com - Last updated - 15 Jun 2017 
'Requires code function from http://www.rondebruin.nl/win/s1/outlook/openclose.htm
Dim OL As Object
Dim olInsp As Object
Dim wdDoc As Document
Dim oRng As Range
Dim EmailItem As Object
Dim Doc As Document
Dim oCC As ContentControl
Dim sProvider As String, sNPI As String, sDateRng As String

    Application.ScreenUpdating = False
    Set OL = OutlookApp()
    Set Doc = ActiveDocument
    Set oCC = Doc.SelectContentControlsByTitle("ProviderName").Item(1)
    If oCC.ShowingPlaceholderText Then
        MsgBox "Enter Provider"
        oCC.Range.Select
        GoTo lbl_exit
    End If
    sProvider = oCC.Range.Text

    Set oCC = Doc.SelectContentControlsByTitle("NPINumber").Item(1)
    If oCC.ShowingPlaceholderText Then
        MsgBox "Enter NPI Number"
        oCC.Range.Select
        GoTo lbl_exit
    End If
    sNPI = oCC.Range.Text

    Set oCC = Doc.SelectContentControlsByTitle("DateRange").Item(1)
    If oCC.ShowingPlaceholderText Then
        MsgBox "Enter Date Range"
        oCC.Range.Select
        GoTo lbl_exit
    End If
    sDateRng = oCC.Range.Text

    Set EmailItem = OL.CreateItem(0)
    Doc.Save
    With EmailItem
        .To = "emailaddress"
        .Subject = "Report Request"
        .BodyFormat = 2
        Set olInsp = .GetInspector
        .Display 'do not delete this line
        Set wdDoc = olInsp.WordEditor
        Set oRng = wdDoc.Range
        oRng.Collapse 1
        oRng.Text = "Hello Robert and Lisa." & vbCrLf & _
                    "I'm writing to request that reports be run on the provider and time period listed below." & vbCrLf
        oRng.Collapse 0
        oRng.Text = sProvider & Chr(32) & sNPI & Chr(32) & sDateRng
        '.Send ';Restore after testing
    End With
lbl_exit:
    Application.ScreenUpdating = True
    Set Doc = Nothing
    Set wdDoc = Nothing
    Set oCC = Nothing
    Set oRng = Nothing
    Set olInsp = Nothing
    Set OL = Nothing
    Set EmailItem = Nothing
    Exit Sub
End Sub