So this feature I haven't documented, but has existed for a while.
You can basically replace any text with part of a command.
For example: Say I want to buy $10,000 worth of Doge.
replace buyusd amount: buy amount/askprice
And then to execute from now on, I'd just go:
Lets go back over that again. In place of
amount, I've added the buy command, and put a calculation of
amount - being the figure I'm going to enter when I execute, divide by the current bidprice, which is the price we will obviously start getting filled at.
replace buyusd amount: buy amount/askprice replace sellusd amount: sell amount/bidprice
And then just:
A few people asked for the example above, to be able to size positions in USD, especially for altcoins. But this feature allows you to release new features such as that yourself.