How do I find the x and y coordinates of a string on-screen

I am creating a fill in the blank question module for a game. I have a text container that contains a question, and I want to be able to find a certain string. For example a dot a couple of dashes and then another dot. (._____.). Once that string is found I want to put a textbox, where the string was. I don't know how to do this in construct 2. Any ideas on how I can achieve this with or without creating a plug in. I'm open for any suggestions.

something like this ?

Well that would be part of it. But what I was looking for is to replace that string with an actual textbox once that certain string was found. The problem I have is how do I get the actual XY coordinates of that string to create a textbox in that spot. Where the user could type their answer into the textbox. Sorry if I wasnt clear in my earlier post.

MissingWordXY

Wow. Great job. I didn't even think to implement it the way you did it. If there was a way to give you all my badges and reputation I would. Thanks a lot this really helped me out.

Ander89 ...maybe you do not have to use a textbox..

just a thought.. MissingWordXY_2.capx