How to set cell format in footer Grid c++ Embarcadero?

Question

C++ / C#

Good afternoon!
I can’t set the format for the calculated cells in the Grid footer, I
calculate the value in the cell

ASender->DataController->Summary->FooterSummaryValues[5] = ASender->DataController->Summary->FooterSummaryValues[11]/ ASender->DataController->Summary->FooterSummaryValues[0];

trying to set output format

ASender->DataController->Summary->FooterSummaryValues[5] = FormatFloat("0.#",ASender->DataController->Summary->FooterSummaryValues[5].VDouble );

but if I apply this format, but in the cell I just get "0"
in the properties of the Format cell, I also set 0. # there is no result