You are unable to create a new cross-tab report from a listing report, only from another cross-tab report.

You cannot sort by the total column because the Top N / Group Expert is disabled for cross-tab reports because there aren't any actual groups. Perhaps a better solution for the report you are writing is to create formulas for each of your columns (for example: if Location Code = "A" then Invoice Amount else 0), and another formula totalling each of these to get a total for the row. You would then subtotal each of these formulas by whichever field you require (ie the 'row' field you had in your cross-tab) and hide the detail section. This would duplicate for the most part a cross-tab report.

Then, to sort by ascending (or descending) totals, use the Top N / Group Expert, and choose Sort All and the sum of 'Total' formula.

The Help files are only suggesting that the steps for creating a custom cross-tab report listed below the sentence you are quoting would be different if you were to make a cross-tab report based on either a dictionary or another cross-tab, rather than the accpac.ssi database.

This won't exactly duplicate a cross-tab as you have to know beforehand how many columns will be created, but otherwise this is the direction to take.