Get the number of a line in a textField

Hi,

is there a way to find the number or of a line in a textField that contains a certain string?

I can find the string using

string.search();

But then I would like to find where the line is in the textfield and scroll it dynamically.

I found

numLines

but that is only the number of lines in a textField.

thanks,

Jerryj.