Return a value from another worksheet using an index formula

Hello,

i am trying to do what i thought was a simple return value. - turns out not for me 😞

as you can see below in column b i have a set of 'dynamic' sheet names called up by a index formula. this column is dynamic and will update as the sheet names change per project. i want to return a value from the same cell everytime but on differently named worksheets -  using this column info.

exampl. 

i want to return the value in worksheet J01 Welcome Desk A601 Cell O134. 

as the worksheet changes name on a different project, i want to return the same cell value in "B4" O134

and so on and so forth down column b

hope that makes sense.