Script Batch plot Problem

I use a scripting program for batch plotting. The problem I'm having is when running the script it comes across an open drawing in the batch; the script doesn't know how to deal with this. The question WOULD YOU LIKE TO OPEN THE FILE READ-ONLY could be answered YES with the first line in the script and it would solve it but when it gets to an unopened drawing having YES as the first command stops it in its tracks.
Here's the script file I'm using
TileMode 0 -PLOT y
Oce TDS400 Roll 1.pc3 ISO A1 (841.00 x 594.00 MM) millimeters Landscape NO Extents FIT Center Yes A1.ctb Yes No No No No No Yes
I don't know much about LISP but maybe a bit of code at the start could solve it.
Thanks Mik

Assuming you are in MDI mode, the following bit of code should open the drawing regardless of whether it's currently open or not.
(vlax-invoke-method (vlax-invoke-method (vlax-get (vlax-get-acad-object) "Documents") "Open" "X:\\MyPath\MyDrawing.dwg") "Activate")
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Thanks for the quick reply. But it doesn't seem to work!
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Works here. What version of AutoCAD?

ADT 3.3 I think the problem is that the script running program concerns itself with opening the drawings, so by the time the code kicks in its already too late.
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