Append & delete text in the middle of a file

[Heinz]

Hi,
I'm trying to replace a value that's in the middle of a text file (using class
File: std.stream.Stream). I'm able to set the cursor position to the beginning
of the value but in order to replace it i must delete it and append text,
there's no way or members to delete chars with the stream class neither append
text (except at eof). The provided write operations replace the value but it
also replaces other text because the data to write is longer than the original
value.

Does anybody have an idea to help me?

Thanx guys.