While there is no specific command to do that, you could do it with a loop using a search that is restricted to the same line. Find_text has a parameter that allows you to specify the number of lines to search. You could move the cursor to the beggining of the line, then search that line for a comma, seven times, then make your substitution.
I am certain that you could do this with a perl regular expression,but I am not so good with those. You might be able to do this with a unix regular expression like:
You can just use 1 as the line count parm and it will stay on the line.
Find_Text( ‘,’, 1, _Backward) integer function
Though you may want to test the result of Find_Text for success in case the line runs out of commas before 7 are found.
You may find additional info if you open the Cmac language help file and search for Search And Replace Function List.