Another way of addressing the same problem is to use the ideographic description characters introduced in Unicode 3.0.

This approach allows you to draw a picture showing what are the various components of the character you can’t represent, and where they appear. The lower line on the slide shows how you would describe the large character near the top. Note that this is interpreted recursively.

Note also, that this should not be treated as in any way equivalent to an existing ideograph when collating strings.