need to append string in a list

[Jannat]

Hiya

Would like to know any method to insert a string of text in a database list by first locating a specific word and appending a string every 3rd line after it. I've tried,but still some problems. The word displays in several blocks of text,i want to insert the string in each block on the 3rd line. guys can help for this

any help will be really appreciated...

[Zecho]

first of all need a better knowledge of your pattern. first word should always start at the beginning of the line in line 1 of the block
but am bit confused if it possible to search just for first word at the beginning of the line but not frustrated about whether it's the first line of the block

[MindSpace]

well it's bit confusing..
to explain at what level you are working,,i don't exactly any idea what you mean by this "block" of text?you wish to modify only every 3rd line?
can you write more regarding your situation