Use find result without ./

You only have to change one character in your command:

find * -type l -name '*.h' -exec ln -s /sourcedir/{} /destinationdir/{} \;
#    ^

Use the standard syntax, like:

S=/sourcedir D=/destdir find . -type l -name '*.h' -exec sh -c '
  for i do
    ln -s -- "$S${i#.}" "$D/$i"
  done' sh {} +

If you want to use GNUisms, you could do:

find . -type l -name '*.h' -printf '/sourcedir/%P\0/destdir/%P\0' |
  xargs -r0n2 ln -s

Or if /sourcedir is the current directory:

find "$PWD" -type l -name '*.h' -printf '%p\0/destdir/%P\0' |
  xargs -r0n2 ln -s

find will print names relative to the paths you provide as arguments. In this case, the path is ., so all the names will begin with ./. To get absolute paths, you need to provide an absolute path as input:

find "$PWD" -type l -name '*.h'

This command uses the $PWD environment variable, which contains the absolute path of the current working directory, so it should preserve the meaning of your original command.

find . -type l -name '*.h' -print0 | cut -z -c3- \
    | xargs -0 -I '{}' ln -s '/sourcedir/{}' '/destinationdir/{}'

man find

• -print0 print the full file name on the standard output, followed by a null character.

man cut - remove sections from each line of files

• -z line delimiter is NUL, not newline.
• -c select only these characters.
• N- from N'th byte, character or field, counted from 1, to end of line.

man xargs - build and execute command lines from standard input.

• xargs [options] [command [initial-arguments]]
• -0 Input items are terminated by a null character instead of by whitespace, and the quotes and backslash are not special (every character is taken literally).
• -I replace-str Replace occurrences of replace-str in the initial-arguments with names read from standard input. Also, unquoted blanks do not terminate input items; instead the separator is the newline character. Implies -L 1.
• -L max-lines Use at most max-lines nonblank input lines per command line.