regex - Removing 3 specific characters, if present from the start of a string VB.net -

i have situation need remove prefix string, if exists.

dim str string = "samvariable"

needs converted variable

easy, trimstart

str = str.trimstart("s"c, "a"c, "m"c)

except...

the string might not start "sam"

example:

dim str string = "saledetails"

this become aledetails

which wrong, how replace

str = str.replace('sam','')

brilliant! now:

example 1:

dim str string = "samvariable" str = str.replace('sam','') str = "variable"

example 2:

dim str string = "saledetails" str = str.replace('sam','') str = "saledetails" (unaffected)

but....

what if:

dim str string = "resample" str = str.replace('sam','') str = "reple"

this wrong again!

so, question is:

how remove "sam" beginning of string only?

i had expected trimstart("sam") work, doesn't

if str.startswith("sam")     str = str.substring(3) end if

not one-liner, easy follow.

Brazell