Please see Writeup Formatting Tips and learn how to use <code> tags to post code.

In attempting to decipher what your code is -- it appears that you have mismatched square-brackets and braces.

The closest to your code that compiles is:

$samstr = {source=>[{abc=>[{uname=>$VAR1,dbcrdn=>$VAR2,paridn=>$VAR3,o
+sath=>$VAR4,}]}]};
[download]

Give that a try.

Also : XML::Simple is a terrible module with inconsistent options.

Consider using an alternative, like XML::Twig.