Bash - how can i pass variable to command and read its output

Question

In my bash script i want to execute command that will find lines in a file that starts with a keyword which is stored in a variable like this:

keyword="key" 
result=(`cat path/to/my/file | grep '^$keyword'`)

Answer 1

Single quotes inhibit substitution. Use double quotes instead:

grep "^$keyword"

Answer 2

Forgive me please, i figured it all out as soon as i posted my question: If has simular issue:

keyword="key" 
find_cmd = "cat path/to/my/file | grep '^$keyword'"
result=(`$find_cmd`)