Solved
Code:
Sub sample2()
Dim srchRng As Range
Dim a As String, b As String, c As String
Set srchRng = ActiveDocument.Content
With srchRng.Find
.Text = "ID:"
.Execute
If .Found = True Then
Dim numberstart As Long
numberstart = Len(srchRng.Text) + 1
srchRng.MoveEndUntil Cset:=","
Dim mynum As String
mynum = Mid(srchRng.Text, numberstart)
End If
End With
c = mynum
For nSectionNum = 1 To ActiveDocument.Sections.Count
Selection.GoTo What:=wdGoToSection, Which:=wdGoToNext, Name:=nSectionNum
ActiveDocument.Sections(nSectionNum).Range.Copy
Next nSectionNum
Dim oRng As Range
Dim oPara As Paragraph
Dim b As String, a As String
Set oPara = ActiveDocument.Paragraphs(5)
Set oRng = oPara.Range
oRng.End = oRng.End - 1
b = oRng.Text
Set oPara = ActiveDocument.Paragraphs(2)
Set oRng = oPara.Range
oRng.End = oRng.End - 1
a = oRng.Text
ActiveDocument.ExportAsFixedFormat OutputFileName:="E:\test\" & b & " " & a & " " & "Sample" & "" & c & ".pdf", _
ExportFormat:=wdExportFormatPDF, OpenAfterExport:=False, OptimizeFor:= _
wdExportOptimizeForPrint, Range:=wdExportAllDocument, From:=1, To:=1, _
Item:=wdExportDocumentContent, IncludeDocProps:=True, KeepIRM:=True, _
CreateBookmarks:=wdExportCreateNoBookmarks, DocStructureTags:=True, _
BitmapMissingFonts:=True, UseISO19005_1:=False
End Sub