Have tried searching for an answer to no avail...

I am looking to create my own custom keyboard shortcut to toggle between worksheets within my workbook.
I prefer to solve this without the use of macros, as I am on an office server that triggers security warnings when macros are in use (plus I want this to be available to me in every workbook I use).

I have found plenty of suggestions for the Ctrl + Page Up or Page Down solution.... what I want is a left-hand only keystroke (similar to using the 'Alt + Tab' in Windows to toggle between open programs on my computer).

Ideally I would use 'Alt + 1' to move to the previous worksheet, and 'Alt + 2' to move to the next.

My search for an answer has lead me to believe that customi keyboard shortcuts in excel are not possible(?)

The closest I have gotten to a solution would be to customise my Quick Access Toolbar, and use 'Alt + *digit*' as a keyboard shortcut to that command... HOWEVER - I am unable to find the required command in the dropdown list of 'All Commands' to achieve the function I'm looking for 'Go To Next worksheet' and 'Go To Prior Worksheet'. Can anyone enlighten me as to what category it's in or what title this command is called?

In short, I'm looking for a left-hand only keyboard shortcut to quickly toggle between my worksheets. The Ctrl + Page Up/Down is a right handed shortcut.

TIA