Convert Text Field with time > 24hours to time

I have an issue with some time data in a text file.
There are several columns that contain summed up time data per person over a month, which can lead to entries like 30:25:51.000 so 30 hours, 25 minutes , 51 seconds.
When I want to transform this textfield into a timefield to sum all lines for that column up I get an error.
Any idea how this works ? Every entry < 24hours is fine.

Would appreciate your solutions.

Best,
Marc