I have several strings like

[![enter image description here](https://i.stack.imgur.com/xMNLI.png)](https://i.stack.imgur.com/xMNLI.png)

I need to match the strings that start wih >=100 and <=300 folowed by space and then any string.

The expected result is

[![enter image description here](https://i.stack.imgur.com/BGGd7.png)](https://i.stack.imgur.com/BGGd7.png)

I have tried with

```
[123][0-9][0-9]\s.*

```

But this matched incorrectly giving 301, 399 and so on. How do I correct it?