Allow calculated values (real, integer) to be stored as document properties Merged

I want to be able to pass calculated values from one data table into a second data table to be used in calculated columns. Currently this is difficult if there is no natural join between the two data tables.

One solution would be to allow document properties to allow values to be generated via an expression. Currently only strings can be supported in this way.

For example, image a table that has 2 columns, Letter and Number
A, 1
B, 2
C, 3
D, 4 etc.

I might want to capture Sum[Number] is a document property and then use that in a calculated column in my second data table. This enhancement request is to enable document properties to be populated via custom expressions that result in numbers (real, integer) rather than strings.

You could consider this as the equivalent to referring to an individual cell in an equation in Excel. You might add a column to your data where you include an absolute cell position (e.g. $A$4 ) which in turn is a calculated value (SUM(A1:A4)