Many accounting and tax preparation software support the TXF Tax Exchange format and thus can exported their own tax files, so it should be quite possible to convert T13 to TXF with At Home accounting software.
Convert H&R Block Tax Software tax return file to Tax Exchange Format.
We found one software available in the database for this conversion.
Microsoft Windows software - convert t13 to txf on Windows
A popular tax preparation software from HRB Digital
Convert from t13 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.