How can I use a variable in another variable in bitbucket pipeline?

[Markus]

Simplified example:

Account variable
A=hello

Deployment variable
B=$A

Expected result: hello
Actual result: $A

What am I doing wrong?

Variants I tried:

B=`$A`
B='$A'
B="$A"
B=${A}

And combinations of these - all with the same outcome.

[Crafton]

Did you figure out how to do this? Or if it's even possible?

[Markus]

doesn't seem possible at the moment. I gave up.