Bind a series of keystrokes to a hotkey

I want to take a sequence of keypresses (including modifiers) and define a single keyboard shortcut to execute the sequence. Can I do that?

I use OneNote for Mac. Notebook navigation by keyboard kinda sucks. In particular there's no easy way to move between tabs on a given notebook.

OneNote lets me press ctrl-tab twice to move focus to the tabset, arrow up or down to select a tab, and shift-ctrl-tab twice to put focus back on the page. I'd like to define shortcuts for a previous-tab and a next-tab action.

Automator doesn't seem to let me define keyboard shortcuts as steps in a process. Am I getting into AppleScript territory here? Are there any third-party tools that'll help?

Ideally I'd like the shortcut keys to only work in OneNote.