If you want to leave a cell value unchanged if a condition is false in Excel, you can use the IF function. The IF function checks whether a condition is TRUE or FALSE, and then returns one value if the condition is TRUE, and another value if the condition is FALSE. In this case, we want to return the original cell value if the condition is FALSE.

To do this, we need to use the following formula:

```
=IF(condition, value_if_true, value_if_false)
```

In our case, the `condition`

will be whatever test we want to perform on the cell value. If the test returns TRUE, then the cell value will be changed to whatever we specify as the `value_if_true`

. Otherwise, if the test returns FALSE, then the cell value will be left unchanged by using the original cell value as the `value_if_false`

. For example:

```
=IF(A1=1, "One", A1)
```

This formula will test whether the value in cell A1 is equal to 1. If it is, then the cell value will be changed to "One". Otherwise, if A1 is not equal to 1, then the cell value will be left unchanged.