I’m not really up to speed with c programing etc, although it is somthing i’m gonna start to look at. Anyway, i dont understand this, from David Gainer Excel 12 blog

Note, the Excel4 API will also respond appropriately to the “$” character, so if an XLL author wants to take advantage of multi-threading, but doesn’t care about the big grid, they do not have to use the Excel12 API.

So does this mean that if i have a xll on my pc now, i can add “$” to it and as i stand here excel will multi thread it????

surly not?