The request here is a familiar one, and it exposes a gap that too many spreadsheet users have quietly accepted. You need to search for a specific account across hundreds of rows, and when you find it, you want to edit that data directly, without breaking the structure of your table. The tools you have tried, a slicer and the FILTER function, each solve half the problem, but neither delivers the full experience. That is not a failure on your part. It is a limitation of the tools you have been given.
A slicer is a great visual filter, but it is not built for typing a value and jumping straight to it. When you have over a hundred accounts, scrolling through a list of buttons is no better than scrolling through the rows themselves. The FILTER function, on the other hand, gives you the search you want, but it returns a separate output. You are editing a copy of the data, not the data itself. Any change you make in that filtered result does not write back to the original table. So you are left with a choice between finding what you need and actually using what you find. That is a false trade-off, and it is one that should not exist in a modern data workflow.
What you are describing is a search bar that behaves like a slicer but with the editing capability of a native cell. You want to type a value, see the matching rows appear in place, and then click directly into a cell to make a change. That is not an unreasonable request. It is the kind of interaction we expect from any well-designed application. The fact that it is difficult to achieve in a traditional spreadsheet environment says more about the limits of that environment than it does about your needs. You are not asking for a complex macro or a custom script. You are asking for a fundamental interaction, search and edit, to work together instead of against each other.
The practical path forward is to look for tools that treat the spreadsheet as a live data surface rather than a static grid. Some newer AI-native spreadsheet platforms are beginning to handle this kind of interaction natively, where the search bar filters the visible rows in place, and edits apply directly to the underlying data. That is the direction this should go. You should not have to choose between a slicer that does not search and a filter that does not edit. Demand the combination. Your data entry work is repetitive enough without adding extra steps to work around a limitation that should not exist. The solution is out there, and it is worth finding it, because your time is better spent on the data itself than on the mechanics of getting to it.