This is a question that reveals a deeper truth about spreadsheets: they were never built to think the way you do. The user wants Column F to behave like a smart assistant, summing C, D, and E when those columns are visible, then letting you override the total with a manual entry the moment they are hidden. That is a completely reasonable, human way to work. But traditional spreadsheet logic cannot do it. It cannot see whether a column is hidden, and it cannot toggle between a formula and a value based on visibility. The user is hitting a wall that thousands of people hit every day: the tool does not adapt to how they actually want to use data.
This is not a failure of the user's imagination. It is a failure of the tool's design. Spreadsheets treat every cell as a fixed rule: a formula or a static number, never both. The moment you type over a formula, the formula disappears. The moment you hide a column, the formulas that reference it simply recalculate with zero instead of pausing. There is no native function like =IF(VISIBLE(C:E), SUM(C:E), INPUT) because the spreadsheet has no concept of what is visible to the user. That is a fundamental blind spot, and it forces people into workarounds, helper columns, macros, manual toggling, that add complexity instead of removing it.
What the user is really asking for is a spreadsheet that understands context. They want a cell that knows when to be a calculator and when to be a data-entry field, based on a condition the user controls. This is precisely the kind of problem that AI-native tools are starting to solve. Instead of forcing the user to write nested IF statements or VBA scripts, a modern spreadsheet should let them describe the behavior in plain language: "When columns C through E are visible, total them. When they are hidden, let me type anything I want." The tool should handle the logic. The user should handle the decisions.
This is what progress looks like, not a slightly faster version of the same old grid, but a tool that meets you where you actually work. The question "Is that possible?" should not be the end of the conversation. It should be the starting point for a better spreadsheet. If you are still wrestling with problems like this one, it is not because you are asking too much. It is because your tool is not asking enough of itself.