IDataGraphT - Axis Properties (Convert/Format Values of the X-Axis)

Hi,

how can I convert/format the labels of the x axis through ArcObjects (C#) ?
At the moment the x-axis is labelled in seconds, but I want to convert these values to 'hh:mm:ss'.

Please check the attachment - the red area should be changed to 'hh:mm:ss'.

How could this be accomplished?

Thanks

Attached Thumbnails