Sending numerical data from an ESP32 to a web page

Here’s some code that’s part of an ESP32 sketch that sends sensor data to a web page on my local internet:
for (byte i=0; i<n; i++) {
ptr +=HR; ptr+=":"; ptr +=MIN_; ptr+=":"; ptr +=SEC*; ptr+=" (";
ptr+=dtostrf(X,8,5,sDayFrac);ptr+=","; // displays more digits*

//ptr+=X*;ptr+=","; // displays only 2 digits to right of decimal point*
This statement: ptr+=X; prints the value in the X array with 2 digits to he right of the decimal point. But the X array contains fractional days, so I want 5 digits to the right of the decimal point. I used the uncommented line with this statement: ptr+=dtostrf(X,8,5,sDayFrac); and it displays a string with the specified number of digits to the right of the decimal point. But, it’s now no longer a floating point value, but a string of characters. So, questions:_

_1. When I use ptr+=X; can the result be used as a numerical value?*
2. If it can be used as a numerical value has it “lost” the digits in the original value or has it kept them and simply displayed them with just two digits to the right of the decimal point?
3. If neither of these options actually transmits a numerical value, how can I do that?

Can you provide an example output of the code above? I see a "
" at the end so it looks like an HTML tag

Hello friend,

You might want to email the vendor that wrote the code, without seeing the code your using its like poking around in the dark with a sowing needle to find a pea.