I am not certain I am following your question. However, we have a similar process where employees cannot submit until the statement cycle is over. They do have to wait to submit, but during the month, they can log into Concur and view the report. They can make changes, upload matching receipts and add any comments that they need to.
They still have to go in to submit after the cycle date ends, but if they've already reviewed everything, it's a much quicker process.
When the expenses load into Concur for the users you work on behalf of, you will have the ability to "complete" the expense by making any changes you need to prepare it for submission. We've found that it's much easier to keep up with expenses as you go than to try to complete a large amount of expenses at the end of the period.