What is the best indicator to use for this?

I've been using a great little indicator that compares recent changes in a pair with other pairs that have the same currencies to help determine which currencies are driving the pairs. I'd like to incorporate this into an EA, but it's proprietary and not available on MetaTrader, so I was wondering what would work well instead?

Basically, I need the indicator to say something like, "Hey, the EUR/USD is going up, the GBP/USD is going up, the USD/CHF is going down, and the USD/CAD is going down." From this, I would guess that the USD is driving the market. I think it would be easy to work with values between -1 and 1, or a percent.

Hopefully this is enough information for someone to suggest something

-Mango

Ok, I've come up with a couple that look like they may fit the bill...

Force Index - "The force of every market movement is characterized by its direction, scale and volume. If the closing price of the current bar is higher than the preceding bar, the force is positive. If the current closing price if lower than the preceding one, the force is negative. The greater the difference in prices is, the greater the force is. The greater the transaction volume is, the greater the force is."

RSI - "RSI = 100-(100/(1+U/D)) Where U is the average number of positive price changes; D is the average number of negative price changes."

I placed those indicators on a chart and they look...visually, exactly the same, with a different scale.

Ok, interesting idea.

I can probably code an EA for this. Let me think it over. The hard part I think is finding a way to automatically detect what pairs are available.

Yeah, I hadn't figured that out either. Worst case scenario, it can be hard-coded.