End of Bath

Hi,
Does anyone have any ideas on how i go about filling in the gap between the end of my bath and the wall. I want to put an L shaped wooden part in and then tile over this...
The first image is what its like looking down on it and the other is a side view. its the awkwardness of drilling in screws in the wood that is throwing me.
Thanks in advance
Ian

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Make the L shaped piece out of 3/4" / 18mil ply, then attach wooden blocks to the wall and floor to attach this to.
Leo