How to convert a RHistory function into a EikonDataApi request?

I'm trying to find out how I can translate the following function found in our excel document.

=@RHistory(".MERF0C4","NDA_RAW.Nda_spread","START:"&$C$46&" END:"&$C$46&" INTERVAL:1D")

Into a request built within EikonDataAPI (C# library)?

Update:

1. I can get the current days value using

eikon.GetData(".MERF0C4", "GEN_VAL10")

but try as I might I can't get historical values. Everything I try returns missing as the only value.

2. This other excel functions retrieves the same info if it helps translate the function.

=@RHistory(".MERF0C4","ROAS.Timestamp;ROAS.Value","START:01-Oct-2020 END:19-Oct-2020 INTERVAL:1D",,"TSREPEAT:NO",W37)

I've tried to extrapolate what it could be but nothing seems to work. I pasted bellow my current attempt with a sample or alternatives I've tried.

var dictParam = new Dictionary<string, string>();

dictParam.Add("SDATE", "01-Oct-2020");

//dictParam.Add("NBROWS", "50");

dictParam.Add("SORT", "ASC");

dictParam.Add("INTERVAL", "1D");

var fields = new List<string>();

//fields.Add("GEN_VAL10");

//fields.Add("TR.ROAS");

fields.Add("TR.NDA_raw");

//fields.Add("FIELDS");

var instruments = new List<string>();

instruments.Add(".MERF0C4");

var abdc = eikon.GetDataRaw(instruments, fields, dictParam);