to secure the assigned securities
Assign means allocate, designate, or set.
for example I will assign you to be the class presiden. assign means to hire
Securities lending means the lending of securities from one person to another. People like to sell their borrowed securities quickly for a profit, then purchase their original security at a lower cost.
To give duties to
It means she sends her regards to you too.
allocate
No. It means that the man is giving her regards.
Appropriate
depends in regards to what? usually means; to come out.
It means shares of a stock (security).
It means best regards
if you are talking about the use of the word "regards" in letters, it would be "bivracha" (בברכה), which means "with a blessing".