Writing to a file from a certain point

[thoand]

hi,

I am trying to write to a file,
Is it posible to write from a certain point.

eg.
Jump over the first 7 caracters/bytes and start writing from there.

I use : fseek() to read from the file from byte 7.
this did not work when I used fputs() the first 7 bytes
was overwriten with whitspaces.

Hope anyone can help,

regards Thomas.