Selecting ranges across frozen and non-frozen area

http://6pac.github.io/SlickGrid/examples/example-frozen-columns-and-rows-spreadsheet.html

I want to select range by drag in above example as follows: 

```
From : {
 Row: 2,
 Cell: 2
}
```
```
To : {
 Row: 12,
 Cell: 6
}
```

The selection stops at
```
 Row: 6,
 Cell: 2
```