position of the number

did you tried the indexOf(); method of String class?

I.e, when you have got the contents of the file in a string, you just need to do indexOf(<string to be searched>); , it should display the index of that number in that string

For getting file contents in string
http://snippets.dzone.com/posts/show/1335
http://www.kodejava.org/examples/52.html

I guess you mean, you have a text file ('I had a notepad'!) and you are trying to do the operation you mentioned using java.
If that is the case, you can use the following steps to do this (may not be the best solution, but it should be enough and easy for a 'new to java programming' person :) ):
1. Read contents of the text file in java and get the whole data in a String.
2. Use the split function of String giving ',' (comma) as a separator. This function returns String array.
3. Now you can find the number you want and the index of the array for that number would be the position.

Hope this helps.

If you want to find the position of the number (assuming the numbers will be separated by comma), then after you have read the file into a string, split the string with commas to get the array of number.
see this link on how to get its index
http://www.java-forums.org/new-java/12254-direct-way-get-index-array.html

use Scanner, which is optimal than split... check this example, http://www.javapractices.com/topic/TopicAction.do?Id=42

you would use "," as delimite than "=" in the example!

//I can search for a particular number
How r u searching the no?
Send the code. It'll be easier to find out what problem ur facing to find the index...

@su_mu

this code works perfectly.... can you tell me how to search for multiple numbers...

search three numbers at a time...