Of course it's not possible, all the system blocks are what they are - I update them from time to time, they are not meant to be updated by the user.
Well, here is some old information, now I'm not sure you will understand something, but... at least it's something: https://fxdreema.com/documentation/libr ... y%20studio
Basically you can open this tool, give a new block name, hit "New", write some code and you will got a new block. All the code is written in a variable, so you should define variables as local or static, global variables also can be used.
There are few keywords, this is the code for Buy now for example:
SetSymbol(SYMBOL);
//-- stops ------------------------------------------------------------------
double sll=0, slp=0, tpl=0, tpp=0;
if (StopLossMode=="fixed") {slp=StopLossPips;}
else if (StopLossMode=="dynamicPips") {slp=~dpStopLoss~;}
else if (StopLossMode=="dynamicDigits"){slp=toPips(~ddStopLoss~,SYMBOL);}
else if (StopLossMode=="dynamicLevel") {sll=~dlStopLoss~;}
if (TakeProfitMode=="fixed") {tpp=TakeProfitPips;}
else if (TakeProfitMode=="dynamicPips") {tpp=~dpTakeProfit~;}
else if (TakeProfitMode=="dynamicDigits") {tpp=toPips(~ddTakeProfit~,SYMBOL);}
else if (TakeProfitMode=="dynamicLevel") {tpl=~dlTakeProfit~;}
//-- lots -------------------------------------------------------------------
double lots=0;
double pre_sll=sll; if (pre_sll==0) {pre_sll=SymbolAsk(SYMBOL);}
double pre_sl_pips=toPips(SymbolAsk(SYMBOL)-(pre_sll-toDigits(slp,SYMBOL)));
if (VolumeMode=="fixed") {lots=DynamicLots(VolumeMode, VolumeSize);}
else if (VolumeMode=="block-equity") {lots=DynamicLots(VolumeMode, VolumeBlockPercent);}
else if (VolumeMode=="block-balance") {lots=DynamicLots(VolumeMode, VolumeBlockPercent);}
else if (VolumeMode=="block-freemargin") {lots=DynamicLots(VolumeMode, VolumeBlockPercent);}
else if (VolumeMode=="equity") {lots=DynamicLots(VolumeMode, VolumePercent);}
else if (VolumeMode=="balance") {lots=DynamicLots(VolumeMode, VolumePercent);}
else if (VolumeMode=="freemargin") {lots=DynamicLots(VolumeMode, VolumePercent);}
else if (VolumeMode=="equityRisk") {lots=DynamicLots(VolumeMode, VolumeRisk, pre_sl_pips);}
else if (VolumeMode=="balanceRisk") {lots=DynamicLots(VolumeMode, VolumeRisk, pre_sl_pips);}
else if (VolumeMode=="freemarginRisk") {lots=DynamicLots(VolumeMode, VolumeRisk, pre_sl_pips);}
else if (VolumeMode=="fixedRisk") {lots=DynamicLots(VolumeMode, VolumeSizeRisk, pre_sl_pips);}
else if (VolumeMode=="fixedRatio") {lots=DynamicLots(VolumeMode, FixedRatioUnitSize, FixedRatioDelta);}
else if (VolumeMode=="dynamic") {lots=AlignLots(~dVolumeSize~);}
//-- send -------------------------------------------------------------------
int ticket=BuyNow(SYMBOL, lots, sll, tpl, slp, tpp, Slippage, (MagicStart+OrdersGroup), MyComment, ArrowColorBuy);
if (ticket>0) {~next~} else {~error~}
Use ~next~ where next blocks should be executed
Use ~inext~ for yellow output
Use ~error~ for gray output
Use ~MyParameterName~ to get the value of any parameter. In the help you will see ~f:Parameter~ - this does not work anymore.
Use ~X~ to get the ID of this block
I think those are the general ones. All these are replaced with something else while building the EA.
You can create custom functions, even with the same name as those I have created. In this case mine will be automatically renamed in system blocks, but still used.
I will not recommend to use Predefined parameters.
In this field below the code you can define global variables for this block. better define them one in a row... or better use static variables.
I can recommend to use integer values for select (options) type of parameters. Here I used string values fot this VolumeMode, which looks fine, but it slows down the EA. Especially when used in blocks that are executed on every tick. At least Buy now is not one of these 
Уж трябва да прави нещата лесни, а често се плаша като видя някой проект.