$readmemh & parameter workaround?

Hi,

I am trying to use a parameter with $readmemh, for example:

parameter rom_file = "data.txt"
...
$readmemh(rom_file, rom);

Which gives the error:

Error (10853): Verilog HDL error at rom_single.v(31): argument 0 to $readmemh must be a string literal

I would like to be instantiate the same ROM module multiple times with different files, so are there any suitable work arounds or solutions to the issue?

I have seen this issue raised before, but no suitable workaround has been suggested

Thanks, Matt