how to obtain ENTH form values of Capacity?

[biblo]

Hi everybody
I have the following data:
MPTEMP,,20,100,200,400,750,850
MPTEMP,,1000,1200,1400,1490,1570,1700
MPTEMP,,5000
MPDATA,c,1,,450,480,520,590,650,1400
MPDATA,c,1,,650,650,650,650,3400,650
MPDATA,c,1,,650
I have phase change in my programme so i need to use the enthalpy instead of the capacity.
How to calculate those of the enthalpy?
MPDATA,enth,1,,?,?,?,?,?,?
MPDATA,enth,1,,?,?,?,?,?,?
MPDATA,enth,1,,?
thank's in advance
Barha.