Convert list of single nucleotide coordinates (hg38) to nucleotides

[keaunym]

I have a list of 6,634 nucleotide coordinates such as chrY:2655296 (chrY:2655296-2655296), just the single nucleotide, that I want to convert to the actual nucleotide at that position. What is the simplest easiest way, especially for someone new to R? Better yet if there is an online tool, please let me know. I spent the last 8 hours searching for a solution and trying different options and came up dry. TIA

[technocrat]

See the FAQ: How to do a minimal reproducible example reprex for beginners. Unless someone with biochemical domain knowledge comes across this, it may be unlikely to get answers.

With a reprex, however, it may be possible to attract the attention of general users.

Every R problem can be thought of with advantage as the interaction of three objects— an existing object, x , a desired object,y , and a function, f, that will return a value of y given x as an argument. In other words, school algebra— f(x) = y. Any of the objects can be composites.

Here, x is a list of typeof chr, and y is a list of typeof chr. What is needed is f that that relates one to the other. For that, some domain knowledge is needed.