Write R code-MCMC sampling of excel data

I have 18 excel spreadsheets, each with 70 columns of data. I need to run MCMC sampling of a single integer x the data in each column, until convergence for that column... so 1260 MCMC sampling exercises.  
I am open to running this separately for each of the 18 spreadsheets, but I do not want to run it separately for each data column within each sheet.
I need an R code to efficiently do this. Thank you!
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