Merge multiple cells in a column to strings no more than 100 characters long

I have a list of text references in column C that I need to combine in to comma seperated strings that are no more than 100 characters each (including spaces and a auto-incremented prefix) in column I.

The incremented prefix needs to start at 10 and increment by 10 for each new line as well as include the text "REM" to generate a quick basic type remark statement.

The attached example shows what the final result needs to be but I have no clue where to begin with macro code for something like this. Please help!