see attached excel file. whatever is on sheet1 will be saved as "data4max.csv" every 13 seconds. the old data is overwritten. press ctrl+t to start the macro. to see the vba code press alt+f11 to open the editor. to change the time interval, double-click "Module1" and find the number 13. so maybe put your dde stuff on sheet2 then format for the record to go to max on sheet1.
to get [text] to read .csv without renaming the file, goto your max "init" folder, open "max-fileformats.txt" and add a line like "max fileformat .csv TEXT 0 "CSV Text file" textfile;"
add [filewatch] to the patch. it sends a bang every time the contents of the file has changed (see help). with the max example above, instead of indexing the data with that auto incrementing number (the second pair of [i] below the second uzi) maybe concatenate some things in excel to make a big timestamp int to send the coll for index. to make the index stop resetting to 1, delete the green patch cord going to the lower [i 1].