I need to read the .txt file as raw text or by code to extract the data keyed in the test suite (resource/assertors,....). Is there any way to do that? by code or any editor.
If you have binary format of tst file then there could be a problem, there is no official API to read it. It's very old format, I don't think that is still in use.
There could be also two, newest, formats of tst:
In case of compressed XML you have to unzip it and then you have access to XML, where you can read it as text file. In case of XML, it's just XML, you can read it as pure text file. There is no official API which allows to read it in similar way as SOAtest's GUI to use in code i.e.: in Java.