Excel 2007 : Refer 3 cell’s values & make a cell address function

In my workbook, in Sheet1 I have been using simple Excel function, example: =Sheet2!M17, to get the value from Sheet2. I want to utilize other reference Excel functions In Sheet1 to accomplish the same results. For doing this, I have done following 3 reservations on Sheet1 to be used as:
Cell B3 in Sheet1  will contain worksheet’s tab name from where the value has to be sourced. B3=Sheet2 for above example.
Columns of row#4: starting with column D & going right through columns E, F, G, ……………..  will contain the column# of the source address. So, M will be filled in any column of row#4, say, F4=M.
Rows of column C: starting with row #5 & going down through rows 6, 7, 8, …………….  will contain the row# of the source address. So, 17 will be filled in any row of column C, say, C9=17.
Now, the cell address which would intersect column & row would be located manually, in above example, the intersection cell address is F9 (on Sheet1).
What formula should be filled in such intersecting cells so that they consider all 3 inputs & fills the required value from the source cells?
The source cells contains a value which is either numerical or alphabet/(s) or alphanumerical. The formula should fill the values in case-sensitive form if the sourced value is alphabet/(s) or alphanumerical.
I am using Excel 2003 & it runs under Excel 2007 in “compatibility mode”.
Thanks in advance.
sandeep999