You can easily do this with the help of Excel, but you would be working with CSV (comma-separated value) files.
It involves having ConnectAll write out or read in the value-map list (lookup list) from a CSV file.
An easy process is to create a field map for a single-select (''Priority'' or ''Severity'' for instance), Put in a few value-maps interactively, then EXPORT the mapping (with the single record or two) into a CSV so you can get the format of what needs to be in the table, then open the CSV in Excel, populate it with other corresponding value-maps from your 2 tools, then re-import the CSV back into the mapping as the value-map. Make SURE to save the file as CSV.
You could also save this Excel table to refer back to if you need to change or add some values. Then you can just re-import back on top of your list later to replace.
See section about it here (about half-way down the page - look for ''import/export to csv''):
https://wiki.connectall.com/ca/latest/user-guide/field-mapping