retrieve value from another tab/sheet when I know the column row

[Diviner_Gregg]

See photo.

I have the column and row number. What is the syntax / formula to retrieve the value contained in
!4_Mstr!BD7 .

bd is column 56 and 7 is the row.

I get a spill error.

Thanks.

[#2]

@Diviner_Gregg  Wow that picture is busy but I believe the function you want is INDIRECT()  and to select FALSE for the cell reference type as follows:

=INDIRECT("r"&'4_Mstr'!EF58&"c"&'4_Mstr'!ED58,FALSE)

so inside it builds the text to say the cell reference you want in the format r3c8 but instead of the numbers you want the '4_Mastr'!EF58 cell reference.  I may have those cells backward but I hope you get the idea.