Oh, I didn't take into account that you specified "in the grid", but I think I've worked with grids that offer the ability to specify a separate component whose capabilities are seen in the grid's cells, but I don't remember if the InfoPower grid has this.

I can think of an inelegant work-around I might try if I were desperate: Overlay the float "field" (presumably an edit component) with a text component and capture the pasted characters there and scrub them before putting them in the float field and then move the text component behind the float again. But that's just the first thing that comes to mind. Not sure what event, if any, would work well for initially bringing the text in front of the float, but I guess you'd want to populate it with the string representation of the float. If this is an FMX app, there's probably a better approach because of how you can manage HitTest in a TLayout, and I use those things to create a kind of transparent "sneeze guard" that you cannot do in VCL.