How can I interpret this VB6 code? - vb6

Question

I inherited a VB program that prints shipping labels. We need to update the barcode that gets printed and I'm trying to understand what the existing program is doing. There is a bunch of "WrittenData" (stored as "s") that seems to contain the Postscript code to produce the labels, but I haven't found anywhere that specifies the meaning of half this stuff.
Public Function PostScriptItem(address As Variant, Optional intPageNumberOut As Integer = 1, Optional intPageNumberIn As Integer = 2) As String
' 0 - MatchUpId
' 1 - Our Barcode
' 2 - Outgoing PostNet Code
' 3 - Outgoing Line 1
' 4 - Outgoing Line 2 (optionally EMPTY)
' 5 - Outgoing Line 3
' 6 - Outgoing Line 4
' 7 - Outgoing PlaNET Code
' 8 - Incoming PostNet Code
' 9 - Incoming Line 1
'10 - Incoming Line 2 (optionally EMPTY)
'11 - Incoming Line 3
'12 - Incoming Line 4
'13 - Incoming PlaNET Code
'14 - Title Id
'Escape Parenthesis and Backslashes
Dim tPos As Integer
For tPos = 0 To 14 Step 1
address(tPos) = Replace(address(tPos), "\", "\\")
address(tPos) = Replace(address(tPos), "(", "\(")
address(tPos) = Replace(address(tPos), ")", "\)")
Next tPos
Dim s As String
Dim pos As Integer
Dim fsize As Integer
Dim strBarcodeCaption As String
strBarcodeCaption = address(1) & " " & address(14) & " " & address(0)
pos = 50
fsize = 12
s = s & "%%Page: " & CStr(intPageNumberOut) & " " & CStr(intPageNumberOut) & vbCrLf & _
"<< /Duplex true >> setpagedevice" & vbCrLf & _
"<< /Tumble true >> setpagedevice" & vbCrLf & _
"%%BeginPageSetup" & vbCrLf & _
"180 rotate" & vbCrLf & _
"/pagelevel save def" & vbCrLf & _
"%%EndPageSetup" & vbCrLf & _
"newpath" & vbCrLf & _
"-338 -205 translate" & vbCrLf & _
"/Courier-Bold findfont 6 scalefont setfont" & vbCrLf & _
"newpath" & vbCrLf
s = s & "32 104 moveto (" & strBarcodeCaption & ") show" & vbCrLf & _
"newpath" & vbCrLf
s = s & "12 -450 translate" & vbCrLf & _
"62 104 moveto (" & strBarcodeCaption & ") show" & vbCrLf & _
"newpath" & vbCrLf & _
"30 80 moveto (^104" & address(1) & ") (height=0.3) code128 barcode" & vbCrLf & _
"newpath" & vbCrLf
s = s & "/Helvetica findfont 11 scalefont setfont" & vbCrLf & _
"0 " & CStr(pos) & " moveto (" & address(3) & ") show" & vbCrLf & _
"newpath" & vbCrLf
pos = pos - fsize
If address(4) <> Empty Then
s = s & "0 " & CStr(pos) & " moveto (" & address(4) & ") show" & vbCrLf & _
"newpath" & vbCrLf
pos = pos - fsize
End If
s = s & "0 " & CStr(pos) & " moveto (" & address(5) & ") show" & vbCrLf & _
"newpath" & vbCrLf
pos = pos - fsize
s = s & "0 " & CStr(pos) & " moveto (" & address(6) & ") show" & vbCrLf & _
"newpath" & vbCrLf
pos = pos - fsize - 5
s = s & "1 " & CStr(pos) & " moveto (" & address(2) & ") () postnet barcode" & vbCrLf & _
"%%PageTrailer" & vbCrLf & _
"pagelevel restore" & vbCrLf & _
"showpage" & vbCrLf
s = s & "%%Page: " & CStr(intPageNumberIn) & " " & CStr(intPageNumberIn) & vbCrLf & _
"<< /Duplex true >> setpagedevice" & vbCrLf & _
"<< /Tumble true >> setpagedevice" & vbCrLf & _
"%%BeginPageSetup" & vbCrLf & _
"/pagelevel save def" & vbCrLf & _
"210 711 translate" & vbCrLf & _
"%%EndPageSetup" & vbCrLf & _
"newpath" & vbCrLf & _
"/Courier-Bold findfont 6 scalefont setfont" & vbCrLf & _
"0 21 moveto (" & address(1) & " " & address(0) & ") show" & vbCrLf & _
"gsave" & vbCrLf & _
"0.5 0.5 scale" & vbCrLf & _
"0 12 moveto (^104" & address(1) & ") (height=0.3) code128 barcode" & vbCrLf & _
"grestore" & vbCrLf & _
"newpath" & vbCrLf & _
"32 0 moveto (" & address(14) & ") show" & vbCrLf & _
"newpath" & vbCrLf & _
"/Helvetica findfont 11 scalefont setfont" & vbCrLf & _
"-70 -180 translate" & vbCrLf
pos = 56
s = s & "0 " & CStr(pos) & " moveto (" & address(9) & ") show" & vbCrLf & _
"newpath" & vbCrLf
pos = pos - fsize
If address(10) <> Empty Then
s = s & "0 " & CStr(pos) & " moveto (" & address(10) & ") show" & vbCrLf & _
"newpath" & vbCrLf
pos = pos - fsize
End If
s = s & "0 " & CStr(pos) & " moveto (" & address(11) & ") show" & vbCrLf & _
"newpath" & vbCrLf
pos = pos - fsize
s = s & "0 " & CStr(pos) & " moveto (" & address(12) & ") show" & vbCrLf & _
"newpath" & vbCrLf
pos = pos - fsize - 5
s = s & "1 " & CStr(pos) & " moveto (" & address(8) & ") () postnet barcode" & vbCrLf & _
"%%PageTrailer" & vbCrLf & _
"pagelevel restore" & vbCrLf & _
"showpage" & vbCrLf
PostScriptItem = s
End Function
I need to change the contents of "address(2)" and "address(8)" and use a different font to print those. I tried putting the new font in the projects fonts folder and referencing it the way "postnet" and "code128" are referenced but that left me with an entirely blank label.
The "code128" font seems to get defined in a separate file called "postscript_main.ps" and I have no idea how to incorporate the new font into that, I am really lost and hoping for a clue or a link to some documentation that might get me going in the right direction.