Keep track of an aggregated crypto portfolio performance

I love Portfolio Performance and I’m using it since a couple of months.
I’m trying to track my crypto investments in the easiest way possible but without success so far

I don’t want to track every transaction but just the total value of the crypto portfolio and its evolution and total return of investment

If the total crypto portfolio is worth 100 Euro I was thinking about adding a “virtual” security called “Crypto”, buying 100 shares for 1 Euro each.

If the portfolio at the end of the month is worth 110 I will update the quote manually (110 Euro/100 shares = 1.10 Euro each)

Problem is that if I want to invest more money (or to disinvest) in the crypto portfolio I have to do very complex calculations to be sure to “sell” and transfer to my deposit account just the right amount of shares.

Is there a better way to keep track of the evolution and the real return of investment of my crypto portfolio?

Thanks in advance!