Feeto,
Have you tried creating a variable of type integer, and using the functions
parseInteger(toString($floatvariable))
I'm not sure if there is a function that can convert a float to an integer, but if you convert the float to a string, you can use the function parse integer to convert the string to an integer.
Have you tried multiplying the decimal value by 100.000.000 (10^8) and make that a long?