extract desired data from excel

Hi,

I have to import a column(numerical data) from excel to r in order to do sth. But I only want some of the data as only positive values are desired and I only need 3~4 thousand data from the column contains ~60000 data. What codes can be used to handle the problem?

See the FAQ: How to do a minimal reproducible example reprex for beginners. Without knowing the selection criteria for the 3-4 thousand records, I can only offer that you should read the data into a data frame and then subset out the non-positive values such as

set.seed(137)
example <- rnorm(100)
example
#>   [1]  0.38351988  1.36694695 -0.34520196  1.34915414  0.30299584  0.52072416
#>   [7]  1.14347930  0.21623641  1.13010260 -0.60028028 -0.14577486  1.41999612
#>  [13] -0.52306705  0.31372968  0.92375247  0.57976740 -0.65468328 -0.25365892
#>  [19]  0.12401743  0.30768539 -1.88340763 -0.40932788  0.46336257 -0.87907282
#>  [25] -1.61913940  0.04188530  0.79710495  0.08772988 -1.01104375  0.36415246
#>  [31]  0.83539027  0.18983531  0.94904841  0.23973975  1.22949385  0.19854351
#>  [37] -2.01138853  1.64089925 -0.14161214 -1.13430607  0.61379004  0.31947382
#>  [43] -1.22268494 -0.52783090 -0.59782853  0.99339972  0.72538290 -0.34264566
#>  [49] -0.82195650  0.80545065 -0.09104667  1.56855159  1.31807990  0.75496865
#>  [55]  0.05120691 -0.14081688 -0.44903762 -0.64806657  0.32339424  1.73758146
#>  [61] -0.11614500 -1.96564365  0.22894035 -0.33757066  0.38135888 -0.59391173
#>  [67] -0.36348201 -0.56392373  0.32406079  0.21732873  0.99321482 -0.03079702
#>  [73] -0.45430447 -1.52427799 -0.66796610 -2.45181705  1.90315154 -1.38664684
#>  [79]  0.66778535 -0.02520749  1.79183676 -0.58461648  0.70451121 -1.20841144
#>  [85] -0.59886305 -0.66304341 -1.07750173  1.91298909  0.33429059  1.27895294
#>  [91] -0.23001024 -2.37174631 -0.85945890  0.57656053 -0.60457517  1.07473707
#>  [97]  1.29750035  1.21936564 -0.73489046 -1.17467082
example <- example[which(example > 0)]
example
#>  [1] 0.38351988 1.36694695 1.34915414 0.30299584 0.52072416 1.14347930
#>  [7] 0.21623641 1.13010260 1.41999612 0.31372968 0.92375247 0.57976740
#> [13] 0.12401743 0.30768539 0.46336257 0.04188530 0.79710495 0.08772988
#> [19] 0.36415246 0.83539027 0.18983531 0.94904841 0.23973975 1.22949385
#> [25] 0.19854351 1.64089925 0.61379004 0.31947382 0.99339972 0.72538290
#> [31] 0.80545065 1.56855159 1.31807990 0.75496865 0.05120691 0.32339424
#> [37] 1.73758146 0.22894035 0.38135888 0.32406079 0.21732873 0.99321482
#> [43] 1.90315154 0.66778535 1.79183676 0.70451121 1.91298909 0.33429059
#> [49] 1.27895294 0.57656053 1.07473707 1.29750035 1.21936564