Powershell replace lines stating with given pattern - regex

Question

Background:
I am trying to read a config file and place it in a string variable for further use. For now I've managed to remove the newlines, which was fairly simple. However, I'm having a bit of trouble with removing comments (lines starting with a #).
What I have so far
$var = (Get-Content $HOME/path/to/config.txt -Raw).Replace("`r`n","")
What I've tried
A lot of it is something along the lines of
$var = (Get-Content $HOME/path/to/config.txt -Raw).Replace("#.*?`r`n","").Replace("`r`n","")
( .Replace("(?<=#).*?(?=`r`n)","") , .Replace('^[^#].*?`r`n','') etc)
A lot of the resources I've found have treated how to iteratively read from a file and write back to it or a new one, but what I need is for the result to stay in a variable and for the original file not to be altered in any way (also I'd rather avoid using temp files or even variables if possible). I think there is something fundamental I'm missing about the input to Replace. (Also found this semi-relevant piece when you're using the ConvertFrom-Csv Using Import-CSV in Powershell, ignoring commented lines .)
Sample input:
text;
weird text;
other-sort-of-text;
#commented out possibility;
more-input/with-comment;#comment
Sample output:
text;weird text;other-sort-of-text;more-input/with-comment;
Additional info:
Am going to run this on current builds of Windows 10, locally now I seem to have pwershell version 5.1.14393.693

Answer 1

Split the string at semicolons, remove element starting with a #, then join the result back to a string.
((Get-Content $HOME/path/to/config.txt -Raw).Replace("`r`n","") -split ';' |
Where-Object { $_.Trim() -notlike '#*' }) -join ';'

Answer 2

This might be identical to some of the other responses, but here is how I would do it:
$Data = Get-Content $HOME/path/to/config.txt -Raw
(($Data -split(';')).replace("`r`n",'') | Where-Object { $_ -notlike '^#*' }) -join(';')
Anyway you do it, remember that rn needs to be expanded, so it has to be encased in double quotes, unlike the rest of your characters.

Answer 3

#############solution 1 with convertfrom-string####################
#short version
(gc "$HOME/path/to/config.txt" | ? {$_ -notlike "#*"} | cfs -D ";").P1 -join ";"
#verbose version
(Get-Content "$HOME/path/to/config.txt" | where {$_ -notlike "#*"} | ConvertFrom-String -Delimiter ";").P1 -join ";"
#############Solution 2 with convertfrom-csv#######################
(Get-Content "C:\temp\test\config.txt" | where {$_ -notlike "#*"} | ConvertFrom-csv -Delimiter ";" -Header "P1").P1 -join ";"
#############Solution 3 with split #######################
(Get-Content "C:\temp\test\config.txt" | where {$_ -notlike "#*"} | %{$_.Split(';')[0]}) -join ";"