Yes that can be achieved in Qlik Sense but it isn't directly supported as you describe (yet). What you need to do is load the expression in as variables. You can type this in directly in the Data Load editor but I find it much easier to just create a data set (e.g. Excel spreadsheet or database table) that contain the expression information.
In the Data Load Editor you can use a script like the one below to load the expression as variables into Qlik Sense. Then when you create the measures in Qlik Sense use the 'dollar sign expansion' format to tell Qlik Sense to evaluate the text as an expression. For example if the variable called:
is set to be:
then the expression used for the measure would be:
I've attached an excel sheet with some epression in it an a sample QVF to help illustrate this.
FROM [lib://Desktop/Expression Sample.xlsx]
(ooxml, embedded labels, table is Sheet1);
//* Set Equation variables
//* The following loop allowing for loading numerous variables dynamically,
//* without having to call them by name.
for i=0 to noofrows('VariablesTable')-1
LET var_name= peek('VariableName',i,'VariablesTable');
LET $(var_name) = peek('VariableValue',i,'VariablesTable');
TRACE Load Variable: $(var_name) = $($(var_name));
Drop Table VariablesTable;