As the chaps said it is really a locksmiths job but you can do it yourself if you feel confident. I would remove the strip as you said and take it to a double glazing firm to id it for you and they should be able to order one for you costing about £100. Or try
www.multipointlocks.co.uk Fitting is reverse process but it will need to be cut down in length to match the door. If you are lucky to of matched it exactly then that should be it. If however it has been upgraded you may need to adjust the stays on the frame. When this happens on some makes especially Winkhaus it can be tricky. Good Luck! Where abouts are you anyway?
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