Table numbering: subsection arabic and table no. alph

[Christian Liesen]

Hi,

sorry for asking, but I could not find any hints on this list or in the 
Embedded Objects-Manual on how to change table numbering to a mixed mode 
of arabic and alph.

I have several tables in a subsection, and I want the caption to look like

Table 1.3 a: foo
Table 1.3 b: foo

and so on, with 1.3 being the subsection and a,b,... as the table numbers.

Any ideas on how to do this or where to look?

Many thanks,
-- Christian