Getting days in dd:hh:mm:ss to display as total hours above 99

Hey folks,

Working on a big data set of times elapsed, and I was wondering if there was a way to have more than 2 digits displaying the amount of days spent on something. I know the total time frame is approximately 525,600 hours worth of time, but the data displays in dd:hh:mm:ss so I've been sticking to said format. Would there be a way to convert this into say hhhhhh:mm:ss?