Include LaTeX preamble in pandoc header file
I'm investigating zettlr as an alternative to Ulysses for writing my PhD thesis. Using Ulysses I used a shell script to use pandoc to convert the Markdown to PDF, but could use
pandoc -H /path/to/preamble.tex ...
to include additional LaTeX packages and commands.
I've tried editing the Advanced Pandoc command to do the same, but get an error despite trying several things (enclosing the file in quotes, using the full option instead of -H, etc).
Is this possible, or do I need to create my own LaTeX template?