If you are in need of conversion of old .123 documents to some of the more recent document formats, like .doc from MS Word, you will need to use some of the dedicated Lotus document conversion utilities, such as ABC Amber Lotus Converter.
Convert Lotus 1-2-3 spreadsheet to Microsoft Word document (prior version 2007).
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert 123 to doc on Windows
A converter for older Lotus documents
Convert from 123 file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.