variable + decimal

[savnik]

I have a variable as word
XL VAR WORD
LO VAR XL.LOWBYTE
HI VAR XL.HIGHBYTE
and a decimal number.
How can to add the decimal to variable and after to write to eeprom;
like this : 13000(variable) + 622,784(decimal - is always the same number) = 13622,784
The decimal 622,784 is from division 38,924/0,0625