I would expect the data to be as safe in excel as it was in Lotus.
Verify that your conversion to excel worked ok.
(Depending on your version of Lotus, you may have to save it as an excel file
(while in Lotus) or an earlier version of Lotus, so that excel can open it.
(Excel doesn't open .123 files.)
And keep backups.
(I've found the biggest threat to the integrity of my data is me--not the
application! I can screw up really, really fast.)