Build reference to different worksheet by extracting cell text

Hi,

I like to dynamically build a reference to a worksheet called "1"and read the contents of cell D3.

Usually this would read ='1'!D3, however I need to build the reference to the worksheet ("1") dynamically by reading the last character of a cell in the current worksheet, eg:

J9: Name 1


I've tried using =RIGHT(J9,1)!D3 or ='RIGHT(J9,1)'!D3 to create the reference, however this doesn't seem to work. Any ideas?

I think I might have answered my own question.

I now have the following and it seems to work:
=INDIRECT(RIGHT(J10,1)&"!D3")

However, despite reading an explanation, I'm not quite sure what the indirect function actually does?
Anyone have a good explanation?

Thanks!