Is it possible in excel using any formula to subtract (or whatever appropriate terms we can call it) from one cell to another so that the third cell will contain the rest of the portion. 
For example, If `Range("A1")` contains `"I am not sure"` and `Range("B1")` contains `"not sure"` and as a result the `Range("C1")` will have `"I am"` when subtraction is performed.

Original data are like:

```
ColumnA            ColumnB   
I am not sure      not sure
The sky is blue    is blue

```

Applying any excel formula, after subtracting `Range("B")` from `Range("A")`, The `Range("C")` will contain the rest of the portion like below:

```
ColumnA            ColumnB      ColumnC 
I am not sure      not sure     I am
The sky is blue    is blue      The sky

```