Brk-int is correct for a one time shot at matching, but this is what I have done with wood trim and some cabinets.
What I do is set out a piece of scrap of the new wood and mark it off with a sharpie or just a score mark. Lay out a piece of paper with the same number of blocks. Number each section of the wood with pencil.
Then measure what you use for each test and write it down. This will get you close and mostly reproducible results. I use an tea spoon or similar and just keep track of "parts per total". Time consuming, but works.
Also, sealing the wood or not sealing it before stain makes a difference.
Good luck, enjoy the process as much as the results
