Perhaps this has been discussed in the past.

I have 30 worksheets in an EXCEL file. The #1 worksheet is the main
informational sheet. I'm trying to obtain the formula that would allow me to
retrieve a specific data from any of the given worksheet.

Example: If J7 is 2, I would like for the system to go to worksheet #2 and
obtain the number from cell d39. If tomorrow I change J7 to 25, I would like
it to go to worksheet #25 and obtain the number from d39.

Your assistance is greatly appreciated
Thanks in advance,

Mike