The only "comp" format I remember is the old COBOL comp(utational) fields.
This type of format has several variations, therefore you need to ask which one is required, for example:
or COMP (binary) This is the equivalent of BINARY. The COMPUTATIONAL phrase is synonymous with BINARY.
or COMP-1 (floating-point) Specified for internal floating-point items (single precision). COMP-1 items are 4 bytes long.
or COMP-2 (long floating-point) Specified for internal floating-point items (double precision). COMP-2 items are 8 bytes long.
or COMP-3 (internal decimal) This is the equivalent of PACKED-DECIMAL.
or COMP-4 (binary) This is the equivalent of BINARY.
or COMP-5 (native binary) These data items are represented in storage as binary data.
On the other hand, you may want to tell the vendor you will be submitting the data in your own format.
The person who says it can't be done should not interrupt the person doing it. -- Chinese proverb