I'd like that it highlight links in e.g. blue & underlined and if I send a link that it automatically colour it blue and underlinde so it shows for other.

Is this possible with mIRC?

If yes, can you help me to script it or link me to an addon?

I've seen it in NNScirpt.

Thanks in advance.

If you want others to see the links that way, then you need to set up an on input script to convert it to underlined and blue. I'm thinking regex is the easiest method to do that and will leave it to someone who knows regex. However, you can also loop through the text for common url text (http,https,www) without using regex and underline/color it that way as well.

Could you please go more into details possibly even step by step explanation since I'm new to mIRC and scripting but would love to learn how it goes. Thanks.