CorelDRAW X4 :: How To Modify Macro To Process All CDR Files In Folder

I am using Coreldraw but in the past I have been able to create the following Macro to do the following

(1) open a file called C:ArtworkC67PSML.cdr
(2) change the text in one field from "Recorded in Ireland" to "Recorded in China"
(3) remove all guideline fields
(4) export the cdr to pdf format and save as new file C:Artwork2C67PSML.pdf

But I would very much like to be able to run the macro on all CDR files in the c:/Artwork folder, how I could amend my code (shown below) to do this ?

Sub Rings()
Dim doc1 As Document    Set doc1 = OpenDocument("C:ArtworkC67PSML.cdr")        Call TextTranslate    ActivePage.Layers("Guidelines").Editable = True    ActivePage.Layers("Guidelines").Shapes.All.CreateSelection    ActiveSelection.Delete    ActivePage.Layers("Guidelines").Activate      
[Code] ......