Indicator lookup last bar

Hi There,

I am building a robot around the Rate of Change Indicator;

So far I got it working to open and close positions when the Value of the ROC is above or below the 0-line:

if (ROC.rocline.LastValue < 0 && !isShortPositionOpen)
            {
                ClosePosition();
                Sell();
                
            }

if (ROC.rocline.LastValue > 0 && !isLongPositionOpen)
            {
                ClosePosition();
                Buy(); 

I would like to only enter a trade if the value of the previous Bar was above/below the 0-Line.

If i set a take profit for example of 10 pips; and it is reach, at the next bar a new position is opened. I want the Robot to wait until the ROC line crosses below/above the 0 line again before opening a new position.

I got this working according to code below, but it will miss opportunaties if I code it like this, as it just sets a window:

if (ROC.rocline.LastValue < 0 && ROC.rocline.LastValue > -0.3  && !isShortPositionOpen)
            {
                ClosePosition();
                Sell();
           
            }

if (ROC.rocline.LastValue > 0 && ROC.rocline.LastValue < 0.3 && !isLongPositionOpen)
            {
                ClosePosition();
                Buy();

So for a buy I would like that I get the value of the ROC of the previous bar to be below 0, the current bar closed above 0 as confirmation.

And for a Sell visa versa; ROC previous bar is above 0, current bar closes below 0.

Thanks in advance.