setFormat

sets a custom format for a cell

void setFormat(number rowId,number columnId,string format, [string page] );

rowId	number	the row id
columnId	number	the column id
format	string	conditions for formatting the cell content, separated by semi-colons (the format details)
page	string	optional, the name of the sheet

$$("ss1").setFormat(2, 2, "[>1000]> 0.0;[>100]Check 0,000.0#;[=0]Nope", "Sheet1");