If have
var='$variable'
how can I expand $variable.
I have tried many thing like duble quotes/braces etc, but nothing worked.
I need the solution ASAP.
We need to see your code to figure out what you're doing.
We do need to see your code, but I'll take a guess anyway.
It seems likely that you need something like "eval" to evaluate the assignment.
variable=preset_value
read line
[user input is <newvar=$variable>]
eval "$line"
echo $newvar
preset_value