How to set loaderInfo params from flash

This is my case
1: I have two swf : a.swf n b.swf
2: I can’t do any coding on a.swf but I can code on b.swf
3: b.swf loads a.swf
4: a.swf takes some params from html
5: Since b.swf now loads a.swf,how can I set loaderinfo params of a.swf from b.swf?

So is there any way I can set loaderinfo params from loading swf to the loaded swf.
Thanks in advance