Search and stop

Hello guys, I'm very new to VBA and I would like to ask a question

I have a text file and i want to search a certain string. then after that i want to stop the process after its found another certain string.

I have provided the sample text file..

Firstly, I would like to find the first textline which is SIFI and I would like it to read all the next textline until it reach the next SIFI. Then, I would like the process to stop if it found the next SIFI.

I'm using MS Excel 2003

May you all help me...