Not sure how you've "imported" the excel file, but the readxl package would help for this. Specifically, the range argument of readxl::read_excel() function which allows you to specify the exact location of the cell(s) you want to import.
E.g., assuming you have an excel file called "my_excel_file.xlsx" in your current working directory, and the data you want to read from it is located in the cell B2 on a sheet Sheet1 :
read_excel(path = "my_excel_file.xlsx", range = "Sheet1!B2")