Dynamic Excel Destination SQL Command in SSIS

Is there a way to specify the SQLCommand for an excel destination dynamically
in SSIS? It appears the "From Variable" option is limited to sheet names and
range names.

I need to iterate through a series of disconnected row/column offsets within
a single sheet. I can very easily calculate the cell references and open the
SQL Command property as SELECT * FROM [Sheet1$B1:B20] changing the actual
rows/columns each time I loop through a subset of values. But it doesn't
appear that I can use a variable or update the SQL Command at runtime.

Is this true or is there a workaround, preferably not involving adding
several dozen named ranges to the sheet, or dropping down to Excel automation.