Visual Basic - Usar comandos ESC/POS

Quiero acceder a una impresora Epson TM con comandos ESC/POS, se que tengo que usar API pero no acabo de comprender el siguiente código que viene en el manual.
¿Alguien podria ayudarme a comprenderlo o indicarme si existe otra manera de hacerlo?
Grácias de antemano.

EPSON
6.2.7. Using ESC/POS commands
The following example shows how you can use the Win32 API to transmit ESC/POS commands directly to the printer.
For more details, refer to the Win32 API help information.
Public Type DOCINFO
pDocName As String
pOutputFile As String
pDatatype As String
End Type
‘'Win32 API external reference definitions
Public Declare Function ClosePrinter Lib "winspool.drv" (ByVal hPrinter As Long) As Long
Public Declare Function EndDocPrinter Lib "winspool.drv" (ByVal hPrinter As Long) As Long
Public Declare Function EndPagePrinter Lib "winspool.drv" (ByVal hPrinter As Long) As Long
Public Declare Function OpenPrinter Lib "winspool.drv" Alias "OpenPrinterA" _
(ByVal pPrinterName As String, phPrinter As Long, ByVal pDefault As Long) As Long
Public Declare Function StartDocPrinter Lib "winspool.drv" Alias "StartDocPrinterA" _
(ByVal hPrinter As Long, ByVal Level As Long, pDocInfo As DOCINFO) As Long
Public Declare Function StartPagePrinter Lib "winspool.drv" _
(ByVal hPrinter As Long) As Long
Public Declare Function WritePrinter Lib "winspool.drv" (ByVal hPrinter As Long, _
pBuf As Any, ByVal cdBuf As Long, pcWritten As Long) As Long
‘##### Source Code #####
Dim lhPrinter As Long
Dim lReturn As Long
Dim lpcWritten As Long
Dim lDoc As Long
Dim sWrittenData As String
Dim MyDocInfo As D