LibreOffice v 4.4
OS Win 7 Home
Please as the answer of ROSt52 seems has solved the issue, can you mark it as correct?
I have not Lotus123 files anymore thswu cannot test but recommend to just give it a try. According to https://wiki.documentfoundation.org/Feature_Comparison:LibreOffice-_Microsoft_Office it is a supported file format. Scroll down to “Minor Feature Differences”.
Thank you. That looks hopeful.
Now to track down ‘How to’. 
Haven’t found an ‘Import’ function and copy/paste of one row of Lotus123 data (ten columns) results in all data appearing in first cell of Calc.
Ah! Couldn’t be simpler. Just opened the 123 file within the Calc window and there it appeared. Only needed to reformat the date cells.
'Think I’m going to like this LibreOffice.,
Many thanks.