Fun challenge - tried to keep things simple until I... Didn't. Opted for a batch macro instead of dynamic replace - so I'm keen to take a look at everyone else's answers and familiarise myself with a new tool!
For those who chose not use a macro or dynamic replace, I recommend that you check that you pass this one:
MDCCXXXII * LXXIX / IX + I * VII = 15210.111
Order of operands matter. @patrick_digan fancy the challenge?