You can format values within the Field Properties dialog (see Types of Data and Field Properties) or within a function invoked from a field where you set the Source to Formula.
The output of a format is a display value and therefore a string.
The infa:format() function has four arguments that enable you to specify the format. For example, if you set the Source to Formula, you can use an expression similar to the following:
Process Designer evaluates the text of the format string and places a value in that format. For example, the format "#,##0.00" tells Process Designer that at least one number to the left of the decimal point must display as well as two to the right. if they are not present, use a zero. Also, depending upon the length, it can insert a comma.