BSB Charts that are not in WGS84 should be automatically converted to that datum when viewed in Offshore Navigator Lite. If OSN Lite is unable to perform this datum shift, a "datum error" will appear in the lower right hand side of the display. Click it for additional details.
You can perform this datum shift by hand by using the "Datum Calculator" found on the "Tools" menu.
But I didn't formulate the question properly. My question is if it's possible to export the chart with a datum different than the one of the original .cap file. I need it to open them into a sonar processing software.