See the sourcecode below and thats the sample output.

How to use:
-Download http://purebasic.jcvsite.com/v4/Forum_Quote_Code.zip
-Extract to your PB folder (ex ../Purebasic/plugins/) or jaPBe plugins folder
-Add it to Tools Menu in your PB
-Just highlight your code and press-c to copy to clipboard and open "Forum Quote.exe" or from your Tools/plugins in IDE
Sample output - (Sourcecode) This is included in the zip archive.
Enumeration
#SYNTAX_Text
#SYNTAX_Keyword
#SYNTAX_Comment
#SYNTAX_Constant
#SYNTAX_String
#SYNTAX_Function
#SYNTAX_Asm
#SYNTAX_Operator
#SYNTAX_Structure
#SYNTAX_Number
#SYNTAX_Pointer
#SYNTAX_Separator
#SYNTAX_Label
EndEnumeration
#Dll = 0
Global highlighted.s
Procedure CallbackHighlight(*Position, length, color)
place.s = PeekS(*Position, length, #PB_UTF8)
place = ReplaceString(place, " ", " ")
If Len(place)>0
Select color
Case #SYNTAX_Text
highlighted + Chr(91) + "color=#0000FF" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93)
Case #SYNTAX_Keyword
highlighted + Chr(91) + "b" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/b" + Chr(93)
Case #SYNTAX_Comment
highlighted + Chr(91) + "color=#008000" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93)
Case #SYNTAX_Constant
highlighted + Chr(91) + "color=#924B72" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93)
Case #SYNTAX_String
highlighted + Chr(91) + "color=#800080" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93)
Case #SYNTAX_Function
highlighted + Chr(91) + "color=#006666" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93)
Case #SYNTAX_Asm
highlighted + Chr(91) + "color=#800000" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93)
Case #SYNTAX_Structure
highlighted + Chr(91) + "b" + Chr(93) + Chr(91) + "color=#59017E" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93) + Chr(91) + "/b" + Chr(93)
Case #SYNTAX_Number
highlighted + Chr(91) + "i" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/i" + Chr(93)
Case #SYNTAX_Pointer
highlighted + Chr(91) + "color=#003264" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93)
Case #SYNTAX_Label
highlighted + Chr(91) + "b" + Chr(93) + Chr(91) + "color=#5A5AAD" + Chr(93)
highlighted + place
highlighted + Chr(91) + "/color" + Chr(93) + Chr(91) + "b" + Chr(93)
Default
highlighted + place
EndSelect
EndIf
EndProcedure
If OpenLibrary(#Dll, "SyntaxHilighting.dll")
SelectedText.s = GetClipboardText()
Length = Len(SelectedText)
*Buffer = AllocateMemory(Length + 1)
PokeS(*Buffer, SelectedText, Length, #PB_UTF8)
If *Buffer
ClearClipboard()
highlighted = Chr(91) + "quote" + Chr(93)
CallFunction(#Dll, "SyntaxHighlight", *Buffer, Length, @CallbackHighlight(), 0)
highlighted + Chr(91) + "/quote" + Chr(93)
SetClipboardText(highlighted)
MessageRequester("Forum Quote", "Code ready to paste in the forum!")
EndIf
CloseLibrary(#Dll)
EndIf