wildcards and A records

[Stromboli]

Hi,

I have a simple question, I understand you can't use regular
expressions in A records but you can use wildcards. If I put a record
like this:

image*.mydomain.com            A  myip

if I user types images.mydomain.com or imagenes.mydomain.com will be
redirected to myip? or I just can a wilcard like *.mydomain.com (it's
the only type I've seen in the examples I looked)

Is there any related problems if you use something like 
image*.mydomain.com

Cordially, 
Strom