how to pass by reference??

[Spencer Doidge]

I really tried to RTM first this time, but I failed.
Can someone give me a hint where in the doc html's it explains how to pass
by reference?
Specifically, I want to do the equivalent of this:

char s[10];

void foo(char *bfr)
{
bfr[0] = 'a';
bfr[1] = 'b';
return;
}

void main(void)
{
foo(s);
return;
}