You can search your posts by clicking the find button on one of your posts or by going to your profile and clicking Find All Posts by username. If that isn't what you are looking for, then you'll need a plugin.
IS there anybody who can code plugin for me?
Thank you. Is there any way how to show them in a list?
I think I understand what you want: just a list of threads in which you have posted. This will require a plugin. Probably it can also be achieved with X-Threads (what cannot), but I don't like the black box magic of that (is personal of course).
I think it will have to be a plugin Ad. I think XThreads actually can't do this