When using the tick-data method of back-testing, Tickstory already embeds the spread value within the resulting data (FXT) file. The spread value can only then be changed using the FXT Editor.
The MT4 Strategy ‘spread’ setting will have no effect except when you are back-testing without using Tickstory. Please have a read of the manual which explains more about how to edit Metatrader FXT files int he section titled ‘MT4 Data Editor’. This thread might also be useful: viewtopic.php?f=2&t=627
So if i open the FXT file and choose for example eurusd 15minutes and put a value into the spread section for example 10 for 1pip spread.
This 15minute file will have after donwloading the spread value of 10 points?