Accessing elements of a string array memory tag in an expression

Hey everyone. If I have a memory tag that is a string array type, lets call it - {[opcServer]opcPath/tagName}
how would I access elements in that array using an expression.

have you tried {[opcServer]opcPath/tagName[elementIndex]} or {[opcServer]opcPath/tagName}[elementIndex] ?

I've tried {[opcServer]opcPath/tagName}[0,0] for a dataset and it didnt work. ill try it for the list and see what i get.

For a string it was:
{[default]Sandbox/stringArray[0]}

and for a dataset it was:
{[default]Sandbox/booleanDataset[0,1]}