I was able to find a way to solve my problem (detailed here) using an Apps Script with a custom function.
If you replace =IMPORTRANGE(spreadsheet_url, range_string)
in your spreadsheet with =DynamicImportRange(spreadsheet_url, sheet_name, range)
and paste the code below into Tools --> Script Editor --> Blank Project, it should work (see this for more information on writing apps scripts).
/**
Usage: =DynamicImportRange(spreadsheet_url, sheet_name, range)
Compare to: =IMPORTRANGE(spreadsheet_url, range_string)
*/
function DynamicImportRange(sheet_url, sheet_name, sheet_range) {
var values = SpreadsheetApp.openByUrl(sheet_url).getSheetByName(sheet_name).getRange(sheet_range).getValues();
return values
};
/**
*/
function RefreshSheet() {
// Update the following two variables to suit your particular situation
var sheet_name = "sheet1"
var range = "A1"
var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(sheet_name);
var formula1 = "Loading...";
var formula2 = sheet.getRange("range").getFormula().toString().replace('"', '\"');
// Note that the following command will delete everything on the sheet.
// If you do not want to do this, you may need to get creative
// with how you specify what gets deleted. You could potentially split
// out the last argument of "formula2" to find the range that needs cleared.
sheet.clear();
sheet.getRange("range").setValue(formula1);
Utilities.sleep(245);
sheet.getRange("range").setValue(formula2);
};
If you want the sheet to be updated on a regular basis, you can set up a trigger by going to Resources --> Current project's triggers in the Apps Script window.