When a text file is being imported to Anki, allow mapping columns in the imported file to the following parameters: “Due”, “Interval”, “Ease”. It means if the imported values of these columns are not empty for a specific card, the card is to be placed in the review queue with Interval, Due and Ease as specified in the imported file instead of being placed in the new cards queue.
This will allow to import a repetition schedule from another program, when switching to Anki.
Here is my related post: Importing externally created schedule from a text file