Where to look (high st) for fantastic work trousers?

[Crystalline]

I need to buy a smart pair of work trousers in the next couple of days, so it needs to be in a physical shop. I want them to wear with brogues and a shirt/blouse and jacket for an important meeting. Probably black, but dark blue or grey or suitably pattered would do. I've lost weight this year and haven't done much shopping but I think I'm around a 10 (possibly 8-10 depending on the shop) and pear shaped. Oh and I'm on the short side of normal.
Where should I hunt, please?

subtly pattered, not suitably patterned, but maybe it amounts to the same thing?

Have you tried Gap? I have some of their True Straight pants, they are really nice fabric - and they do a petite length!