Here's a workaround...admittedly a bit klunky...but I can't think of a way to cajole the randomization sequence created in MODDE to be repeated in JMP. Maybe somebody else knows? So here's how I'd go about getting the MODDE design, with the retained randomization sequence, into a JMP generated design. My thinking is actually a two step merger of my original reply...
Step 1: Create the design in JMP. You still want to do this to retain all the meta data that JMP associates with your factors and responses. You'll want to make sure you have a full understanding of these fields. Things like JMP data type, factor type (blocking, if incorporated into the design,,,) etc. Once created, delete all the rows in the JMP data table...but don't clear out the column headers or any JMP column property data or information.
Step 2: Export the MODDE design and responses, just the actual design, no column headers, or any other information, to say Excel. I'm not sure of the exact format of the 'design' in MODDE. If it's NOT consistent with the format of a JMP generated design, that is each factor has it's own column, each row represents a full treatment combination within the design, then you'll have to manipulate to Excel column by row format to exactly match what JMP would have generated. Make sure the columns in the Excel sheet are in the same sequence left to right as they are in the JMP data table. If you have to export any column headers, delete then from the Excel spreadsheet before proceeding.
Step 3: Copy the entire MODDE design and responses (now in Excel), then do a group paste into the JMP data table.
Step 4: I'd spend a few minutes making sure in the importing process JMP didn't change column properties like JMP data type and modeling type. It's conceivable that say you had a factor called "Supplier" and in the MODDE design they just entered a 'number' like 1, 2, and 3 (for three levels of what we'd call in JMP a categorical factor) and in all the exporting and copy/pasting, JMP kind of 'guesses' the most appropriate JMP data and concurrent modeling type. And depending on what JMP 'sees' when it imports a column may influence what happens. If JMP changes the data type or modeling type to something inappropriate, it's easy enough to change in the column properties menu.
Whew...maybe somebody else has a more elegant solution path?
Once you're done with the above...I'd try and convince whoever created the design in MODDE to get a copy of JMP...maybe they don't know what they are missing?