Check this out.

http://www.woodweb.com/knowledge_base/Staining_and_Blending_Difficult_Woods.html

There's no magic bullet for what you're seeking. I highly recommend securing some alder and do lots of testing. Moreover, write down everything you do so it can be repeated.

I have seen alder stained in both a light walnut and a medium walnut stain that both looks very nice. See if you can get 2 unfinished blocks of alder wood to sample both colors on that way you can get an idea of what it will look like. Good luck

Red alder stains very nicely and it is often used instead of hard maple. So although you can get the color tone of steamed black walnut using a stain on alder, you won't get the rich grain pattern that walnut offers.

I think Lyptus would stain like Black Walnut. That may be the most economical material that has a grain texture similar to Walnut. Alder will never look like Walnut because the grain is way different.