How to use the Idoc number.(generated by prgram) and ALE

Hi All

I have a problem to use Idocs. I go thru the following steps but can not able to see the final output.

1.Create Segment ( WE31)

2.Create Idoc Type ( WE30 )

3.Create Message Type ( WE81 )

4.Assign Idoc Type to Message Type ( WE82 )

5.Make a report which gives us Idoc number.

Now my problem is where this Idoc number can we used .and how to relate this with ALE.

Regards

Manoj