Hi - I know this is a little old but I have been doing a similar thing.
My recommendation is -
- Create 2 Variables - e.g. ATR_Ref_Val & SL_In_Pips both of type double
- Modify/set in a block before the Trailing stop block as in the following
- Then use the SL_In_Pips variable in the Trailing settings

Modify ATR_Ref_Val to your ATR settings
then Modify SL_In_Pips using the FX Dreema function/method toPips(ATR_Ref_Val,CurrentSymbol())
Then in your Trailing Stop you can use the variable SL_In_Pips as the Pips value
Hope that helps - it's how I am doing it

