Index/Match several sheets to one

Hi there,

I have a multi-tab spreadsheet that I'd like to summarise, am trying to use index/match, but this may not be the best option.

I could use a vlookup to pull in by column but sometimes the format of these sheets are not uniform, so pulling in by column is not ideal, rather to index by date (across top) and description (left).

But I can't figure out how to do a index/match for all tabs to pull into SubTot.

Suggestions welcome.

Many thanks, Maddy