Problem with strings

Question

Hi,

I am a beginner and I cannot solve this problem.

I have a multilines textbox (txtOutput) that receive data from the serial port. I can see the data there and all its working fine.

I would like to get the last string from such textbox that is something numeric like" 12" or 1021" and store it into a variable.

Then If the value I get is < 1000 I would like that value to be shown and update textBox2.text otherwhise show and update textBox3.text.

Can someone please help. I would really appreciate.

Kind regards

Felice