I have the source code for an ea that uses what it calls a common cost per point lot size where the lot size for each currency pair is calculated by its cross against the USD. It's a very neat function, however I'd also like to have the ability to enter my own manual lot sizes that will stay consistent without the automatic calculations changing the lot size every time it opens a new position as happens when the currencies change value against the USD.

Ideally as I have the robot trading 3 pairs per group, each pair would have its own input in the robot. For example if I'm running AUDUSD, AUDNZD and NZDUSD as my three pairs, there would be a separate lot size input for each pair. I only employ one group of 3 per robot, so it only needs 3 lot size inputs.

It's not a big change, I just don't know how to do it. Any help would be greatly appreciated, thanks!