Position Building

I need to create a program that will open a position from the moment it is switched on.
The type of the first and all subsequent positions will be calculated on the basis of margin level %

that is, I want to specify in the settings whether the robot should only open buy or only sell items
the lot of the first and all subsequent positions is to be calculated on the basis of margin level %

for example, 

after starting the program, the position should open so large that the margin level was 400%
and the next positions should be opened after exceeding the next margin level, for example 600% if the position earns,
and again by volume the position lot so that the margin level was 400%

if positions lose, and the margin level drops to 100%, the program's task is to close proportionally from each open position that the margin returns to 400%

I would like to be able to determine what level of account balance I use for calculations.
For example, if the real balance of my account is 1000 USD, after determination use calculation based on 100 USD,
all calculations should be made as if the invoice was only 100 USD

Program parameters (variables):

0.Balance to be used [100]
1.We open positions [BUY or SELL];

2.The maximum number of items [x];
3.Use margin level [400%];
4. Next position if margin level >=[600%];
5.Reduce your position if margin level <=[100%];
6.Restore margin level to level [400%]
7.Close all positions if profit [100%]
8.Close all positions if a loss {20%]