Escaping in C-language functions

Hello,

i have a C-language function and need to escape some strings returned
from SPI_getvalue to insert into another query string.
Is there a proper way to do the escaping or should i use
my own functions for that?
Or i'm totally wrong and there's a better way to get the values
from a row and insert it into another table (how to handle \0 values)?

Best regards

--
Andreas 'ads' Scherbaum