I want to format a number to a time value. If my number is 2.5, this equals 2 and a 1/2 minutes, so the formatted number would be 02:30:00 (this includes milliseconds.)

I thought x = format(x, "mm:ss:ff") might work but it doesn't. I'm currently trying to / can't work out "toString" or the "Timespan" (if that's what I should be using). So I thought I'd put this out there to see if anyone can help me out. Thanks.