I want to create a diagonal matrix from the following excel sheet (all values of row 265 of the sheet B)

I used the following codes. Earlier, I read the excel file using library(readxl) and it worked. However, as.vector(as.matrix(USEEIOv1_1_Matrices_B[265,2:389])) didn't return the value from 265. Rather, it returned to different values.

# Rnox from sheet B

Rnox <-as.vector(as.matrix(USEEIOv1_1_Matrices_B[265,2:389]))

Rnox.mat<-matrix(rep(0,150544),nrow=388)

diag(Rnox.mat)<-Rnox.diag

Now, all I want is to have the values from 265 rows as a vector and then make a diagonal matrix form that vector (like identity matrix where all diagonal values are 1). I was wondering if anyone could help me in this regard. Thanks in advance