Help!

How to make a macro who will find every cell (in a specific column - for
example, column B) and erase content, if that content is a number with one,
two, three, four or five digits.

For example:

Cell 1 3858884116322
Cell 2 3856003215644
Cell 3 41862
Cell 4 4569888
Cell 5 499
Cell 6 0


Macro must eliminate (just erase content - not cell) cell 3, 5 and 6 (column
B).

Thanx.